From 7ea56055f76844c3af7d1c8b4b29a9f5d9d8160c Mon Sep 17 00:00:00 2001
From: Lucas Machado <lucas.dpmachado@gmail.com>
Date: Fri, 10 Jul 2026 09:55:09 +0200
Subject: [PATCH] refactor: honest single-walk + dedupe presets + version
 pragma
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

Follow-up PR that honestly delivers what the earlier roadmap PRs
oversold. Everything is behind broadened parity goldens so any drift
is a build failure.

## 1. True single-walk rule engine (fixes spec 005 dishonesty)

The prior "rule engine" PR (#17) shipped an architectural wrapper but
kept the seven per-rule filepath.Walk calls untouched — every rule
still walked the tree via the old Validate* method it was wrapping.
Net cost: 8 walks per run instead of the previous 7.

This commit does the actual conversion:
- Each rule iterates ctx.Tree.Entries in walk order.
- dirStructureRule tracks a skipTracker to preserve filepath.SkipDir
  semantics from the legacy walk (disallowed subtree suppresses
  descendant checks).
- requiredPathsRule and requiredGroupsRule keep their os.Stat / glob
  helpers — the legacy quirk of seeing through ignored directories is
  a parity requirement.
- placementRule and boundariesRule preserve their Successes counter
  quirks (once per (file, rule) pair even on violations).
- The exported Validate* methods stay as thin wrappers over
  runSingleRule(path, rule) so root validator_test.go and any external
  callers keep working.

Broadened parity fixtures cover boundaries, requiredGroups, and
disallowed-subtree SkipDir semantics — three cases the earlier
goldens didn't touch. 21 parity subtests, all byte-identical.

## 2. Init templates now live in one place (fixes template dup)

Deletes the 220-line projectTemplates map in internal/cli/init.go.
`init --type <T>` now reads the same embedded preset files that
`extends: <T>-standard` resolves against, via config.ReadPreset, and
prepends a one-line project-typed header comment. Two ways to reach
the same rules; one source of truth.

- init.go: 322 → 168 lines.
- test/init_presets_test.go proves init output body is byte-identical
  to the corresponding preset AND that init --type go and
  extends: go-standard produce equivalent validation on the same tree.

## 3. Version pragma actually enforced (fixes docs-only mitigation)

The prior mitigation for "old binary + new config with `extends`" was
just a suggestion to add `# requires structlint >= vX.Y` in comments.
Nothing enforced it — users saw the raw yaml `field not found` error.

New internal/config/versioncheck.go parses the pragma from the raw
bytes BEFORE strict parsing and prints an actionable message when the
running binary is older than required. Dev builds (Version=="dev") and
malformed pragmas skip the check.

Tests: 10 in-package unit tests over parse/compare edge cases, plus
2 binary-based end-to-end tests that build pinned binaries with
ldflags-injected versions and prove the error surfaces cleanly.

## 4. Deeper SKILL.md validation

skill_contract_test.go had shallow checks (file exists, frontmatter
delimiter present). skill_deep_test.go adds:
- Frontmatter parses as real YAML with the expected shape.
- Trigger phrases from the description survive block-scalar folding
  (parses YAML first, then normalizes whitespace before searching).
- Every subcommand referenced in setup recipes actually boots via
  app.Run(--help) — catches renames.
- JSON v1 contract mentioned + all four exit codes documented.

## Numbers

167 tests before this PR, 191 tests after. Every existing parity
golden byte-identical. Self-validation still passes.
---
 docs/user/configuration.md                    |  18 +-
 internal/cli/init.go                          | 290 ++++--------------
 internal/config/config.go                     |   6 +
 internal/config/merge.go                      |  23 ++
 internal/config/versioncheck.go               | 111 +++++++
 internal/config/versioncheck_test.go          | 118 +++++++
 internal/validator/engine.go                  | 250 +++++++++++++--
 internal/validator/validator.go               | 275 +++--------------
 test/init_presets_test.go                     |  91 ++++++
 test/skill_deep_test.go                       | 194 ++++++++++++
 .../parity/boundaries/.structlint.yaml        |  17 +
 test/testdata/parity/boundaries/README.md     |   1 +
 test/testdata/parity/boundaries/go.mod        |   3 +
 .../parity/boundaries/internal/db/db.go       |   3 +
 .../boundaries/internal/domain/clean.go       |   3 +
 .../boundaries/internal/domain/model.go       |   6 +
 .../disallowed-subtree/.structlint.yaml       |  13 +
 .../parity/disallowed-subtree/README.md       |   1 +
 .../parity/disallowed-subtree/src/main.go     |   1 +
 .../parity/disallowed-subtree/tmp/leftover.go |   1 +
 .../disallowed-subtree/tmp/nested/deeper.go   |   1 +
 test/testdata/parity/goldens/boundaries.exit  |   1 +
 test/testdata/parity/goldens/boundaries.json  |  33 ++
 test/testdata/parity/goldens/boundaries.text  |  15 +
 .../parity/goldens/disallowed-subtree.exit    |   1 +
 .../parity/goldens/disallowed-subtree.json    |  33 ++
 .../parity/goldens/disallowed-subtree.text    |  15 +
 .../parity/goldens/required-groups.exit       |   1 +
 .../parity/goldens/required-groups.json       |  50 +++
 .../parity/goldens/required-groups.text       |  19 ++
 .../parity/required-groups/.structlint.yaml   |  20 ++
 .../testdata/parity/required-groups/README.md |   1 +
 .../required-groups/cmd/broken/helper.go      |   3 +
 .../required-groups/cmd/complete/main.go      |   3 +
 test/version_pragma_test.go                   |  69 +++++
 35 files changed, 1212 insertions(+), 478 deletions(-)
 create mode 100644 internal/config/versioncheck.go
 create mode 100644 internal/config/versioncheck_test.go
 create mode 100644 test/init_presets_test.go
 create mode 100644 test/skill_deep_test.go
 create mode 100644 test/testdata/parity/boundaries/.structlint.yaml
 create mode 100644 test/testdata/parity/boundaries/README.md
 create mode 100644 test/testdata/parity/boundaries/go.mod
 create mode 100644 test/testdata/parity/boundaries/internal/db/db.go
 create mode 100644 test/testdata/parity/boundaries/internal/domain/clean.go
 create mode 100644 test/testdata/parity/boundaries/internal/domain/model.go
 create mode 100644 test/testdata/parity/disallowed-subtree/.structlint.yaml
 create mode 100644 test/testdata/parity/disallowed-subtree/README.md
 create mode 100644 test/testdata/parity/disallowed-subtree/src/main.go
 create mode 100644 test/testdata/parity/disallowed-subtree/tmp/leftover.go
 create mode 100644 test/testdata/parity/disallowed-subtree/tmp/nested/deeper.go
 create mode 100644 test/testdata/parity/goldens/boundaries.exit
 create mode 100644 test/testdata/parity/goldens/boundaries.json
 create mode 100644 test/testdata/parity/goldens/boundaries.text
 create mode 100644 test/testdata/parity/goldens/disallowed-subtree.exit
 create mode 100644 test/testdata/parity/goldens/disallowed-subtree.json
 create mode 100644 test/testdata/parity/goldens/disallowed-subtree.text
 create mode 100644 test/testdata/parity/goldens/required-groups.exit
 create mode 100644 test/testdata/parity/goldens/required-groups.json
 create mode 100644 test/testdata/parity/goldens/required-groups.text
 create mode 100644 test/testdata/parity/required-groups/.structlint.yaml
 create mode 100644 test/testdata/parity/required-groups/README.md
 create mode 100644 test/testdata/parity/required-groups/cmd/broken/helper.go
 create mode 100644 test/testdata/parity/required-groups/cmd/complete/main.go
 create mode 100644 test/version_pragma_test.go

diff --git a/docs/user/configuration.md b/docs/user/configuration.md
index 73fff35..756168a 100644
--- a/docs/user/configuration.md
+++ b/docs/user/configuration.md
@@ -68,7 +68,23 @@ dir_structure:
 - `placement`, `requiredGroups`, `boundaries` — keyed by `id`. Same ID → child rule replaces the parent's wholesale. New IDs append.
 - Parents resolve depth-first. Chains are cycle-checked and capped at depth 10.
 
-**Compatibility warning:** the `extends` key requires structlint **v0.6.0 or newer**. Older binaries strict-parse the file and reject it with `field extends not found in type config.Config` — pin your CI action and pre-commit rev to a version that supports it, and add a `# requires structlint >= vX.Y` comment at the top of configs that use `extends`.
+**Compatibility warning:** the `extends` key requires structlint **v0.6.0 or newer**. Older binaries would strict-parse the file and reject it with `field extends not found in type config.Config` — a confusing error for the actual problem.
+
+To make old-binary failures actionable, add a `# requires structlint >= vX.Y` comment at the top of any config that uses `extends`:
+
+```yaml
+# requires structlint >= v0.6.0
+extends: go-standard
+```
+
+When a binary older than the pragma sees this comment, it stops **before** strict parsing and prints:
+
+```
+.structlint.yaml requires structlint >= v0.6.0, but running version is v0.5.0.
+Upgrade the binary (go install github.com/AxeForging/structlint/cmd/structlint@latest) …
+```
+
+The pragma is checked before strict parsing, so it works even on binaries too old to know about `extends`. Dev builds (unstamped `go run`) skip the check.
 
 ### Editor autocomplete via JSON Schema
 
diff --git a/internal/cli/init.go b/internal/cli/init.go
index 7721888..0b3fe04 100644
--- a/internal/cli/init.go
+++ b/internal/cli/init.go
@@ -6,11 +6,34 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
+	"github.com/AxeForging/structlint/internal/config"
 	"github.com/AxeForging/structlint/internal/infer"
 	"github.com/urfave/cli/v3"
 )
 
+// projectTypeToPreset maps `init --type` values to preset names in
+// internal/config/presets/. Kept as a distinct map (instead of using the
+// preset names directly as --type values) so the shorter --type flag is
+// still ergonomic and the preset names remain the source of truth.
+var projectTypeToPreset = map[string]string{
+	"go":      "go-standard",
+	"node":    "node-standard",
+	"python":  "python-standard",
+	"generic": "generic",
+}
+
+// projectTypeHeaders is the single-line header prepended to the preset
+// content so the generated config file reads like a starter template
+// instead of a bare preset dump.
+var projectTypeHeaders = map[string]string{
+	"go":      "# structlint configuration for Go projects\n",
+	"node":    "# structlint configuration for Node.js projects\n",
+	"python":  "# structlint configuration for Python projects\n",
+	"generic": "# structlint configuration\n",
+}
+
 // NewInitCmd creates the init command for generating starter configs.
 func NewInitCmd() *cli.Command {
 	return &cli.Command{
@@ -62,12 +85,11 @@ func NewInitCmd() *cli.Command {
 				projectType = detectProjectType(".")
 			}
 
-			template, ok := projectTemplates[projectType]
-			if !ok {
-				return fmt.Errorf("unknown project type: %s (available: go, node, python, generic)", projectType)
+			data, err := renderProjectTemplate(projectType)
+			if err != nil {
+				return err
 			}
-
-			if err := os.WriteFile(configPath, []byte(template), 0o644); err != nil {
+			if err := os.WriteFile(configPath, data, 0o644); err != nil {
 				return fmt.Errorf("failed to write configuration: %w", err)
 			}
 
@@ -78,6 +100,43 @@ func NewInitCmd() *cli.Command {
 	}
 }
 
+// renderProjectTemplate builds a starter config for the requested project
+// type by reading the corresponding preset (source of truth for the
+// baseline rules) and prepending a project-typed comment header. This
+// keeps init's output and `extends:` presets from drifting.
+func renderProjectTemplate(projectType string) ([]byte, error) {
+	presetName, ok := projectTypeToPreset[projectType]
+	if !ok {
+		return nil, fmt.Errorf("unknown project type: %s (available: %s)",
+			projectType, strings.Join(projectTypeList(), ", "))
+	}
+	body, err := config.ReadPreset(presetName)
+	if err != nil {
+		return nil, fmt.Errorf("read preset for %s: %w", projectType, err)
+	}
+	header := projectTypeHeaders[projectType]
+	buf := make([]byte, 0, len(header)+len(body))
+	buf = append(buf, header...)
+	buf = append(buf, body...)
+	return buf, nil
+}
+
+func projectTypeList() []string {
+	out := make([]string, 0, len(projectTypeToPreset))
+	for k := range projectTypeToPreset {
+		out = append(out, k)
+	}
+	// Alphabetical for stable error messages.
+	for i := 1; i < len(out); i++ {
+		j := i
+		for j > 0 && out[j-1] > out[j] {
+			out[j-1], out[j] = out[j], out[j-1]
+			j--
+		}
+	}
+	return out
+}
+
 // detectProjectType guesses the project type from files in the directory.
 func detectProjectType(dir string) string {
 	checks := []struct {
@@ -99,224 +158,3 @@ func detectProjectType(dir string) string {
 
 	return "generic"
 }
-
-var projectTemplates = map[string]string{
-	"go": `# structlint configuration for Go projects
-dir_structure:
-  allowedPaths:
-    - "."
-    - "cmd/**"
-    - "internal/**"
-    - "pkg/**"
-    - "api/**"
-    - "test/**"
-    - "docs/**"
-    - "scripts/**"
-    - ".github/**"
-  disallowedPaths:
-    - "vendor/**"
-    - "node_modules/**"
-    - "tmp/**"
-  requiredPaths:
-    - "cmd"
-
-file_naming_pattern:
-  allowed:
-    - "*.go"
-    - "*.mod"
-    - "*.sum"
-    - "*.yaml"
-    - "*.yml"
-    - "*.json"
-    - "*.md"
-    - "*.txt"
-    - "Makefile"
-    - "Dockerfile*"
-    - "*.sh"
-    - ".gitignore"
-    - ".goreleaser.yaml"
-    - "LICENSE*"
-  disallowed:
-    - "*.env*"
-    - "*.key"
-    - "*.pem"
-    - ".DS_Store"
-    - "*.log"
-    - "*.tmp"
-    - "*~"
-    - "*.swp"
-  required:
-    - "go.mod"
-    - "README.md"
-    - ".gitignore"
-
-ignore:
-  - ".git"
-  - "vendor"
-  - "bin"
-  - "dist"
-`,
-
-	"node": `# structlint configuration for Node.js projects
-dir_structure:
-  allowedPaths:
-    - "."
-    - "src/**"
-    - "lib/**"
-    - "test/**"
-    - "tests/**"
-    - "__tests__/**"
-    - "docs/**"
-    - "scripts/**"
-    - "public/**"
-    - "config/**"
-    - ".github/**"
-  disallowedPaths:
-    - "node_modules/**"
-    - "tmp/**"
-    - "temp/**"
-  requiredPaths:
-    - "src"
-
-file_naming_pattern:
-  allowed:
-    - "*.js"
-    - "*.ts"
-    - "*.jsx"
-    - "*.tsx"
-    - "*.json"
-    - "*.yaml"
-    - "*.yml"
-    - "*.md"
-    - "*.css"
-    - "*.scss"
-    - "*.html"
-    - "*.svg"
-    - "*.png"
-    - "*.jpg"
-    - ".gitignore"
-    - ".eslintrc*"
-    - ".prettierrc*"
-    - "*.config.*"
-    - "Dockerfile*"
-    - "LICENSE*"
-  disallowed:
-    - "*.env*"
-    - "*.key"
-    - "*.pem"
-    - ".DS_Store"
-    - "*.log"
-    - "*~"
-    - "*.swp"
-  required:
-    - "package.json"
-    - "README.md"
-
-ignore:
-  - ".git"
-  - "node_modules"
-  - "dist"
-  - "build"
-  - "coverage"
-`,
-
-	"python": `# structlint configuration for Python projects
-dir_structure:
-  allowedPaths:
-    - "."
-    - "src/**"
-    - "tests/**"
-    - "test/**"
-    - "docs/**"
-    - "scripts/**"
-    - ".github/**"
-  disallowedPaths:
-    - "__pycache__/**"
-    - ".tox/**"
-    - "*.egg-info/**"
-    - "node_modules/**"
-  requiredPaths: []
-
-file_naming_pattern:
-  allowed:
-    - "*.py"
-    - "*.pyi"
-    - "*.toml"
-    - "*.cfg"
-    - "*.ini"
-    - "*.txt"
-    - "*.yaml"
-    - "*.yml"
-    - "*.json"
-    - "*.md"
-    - "*.rst"
-    - "Makefile"
-    - "Dockerfile*"
-    - "*.sh"
-    - ".gitignore"
-    - ".flake8"
-    - "LICENSE*"
-    - "MANIFEST.in"
-  disallowed:
-    - "*.env*"
-    - "*.key"
-    - "*.pem"
-    - ".DS_Store"
-    - "*.log"
-    - "*~"
-    - "*.swp"
-    - "*.pyc"
-  required:
-    - "README.md"
-
-ignore:
-  - ".git"
-  - "__pycache__"
-  - ".tox"
-  - ".venv"
-  - "venv"
-  - "dist"
-  - "build"
-  - "*.egg-info"
-`,
-
-	"generic": `# structlint configuration
-dir_structure:
-  allowedPaths:
-    - "."
-    - "src/**"
-    - "lib/**"
-    - "test/**"
-    - "tests/**"
-    - "docs/**"
-    - "scripts/**"
-    - ".github/**"
-  disallowedPaths:
-    - "tmp/**"
-    - "temp/**"
-    - "node_modules/**"
-  requiredPaths: []
-
-file_naming_pattern:
-  allowed:
-    - "*.*"
-  disallowed:
-    - "*.env*"
-    - "*.key"
-    - "*.pem"
-    - ".DS_Store"
-    - "*.log"
-    - "*.tmp"
-    - "*~"
-    - "*.swp"
-  required:
-    - "README.md"
-
-ignore:
-  - ".git"
-  - "node_modules"
-  - "vendor"
-  - "dist"
-  - "build"
-`,
-}
diff --git a/internal/config/config.go b/internal/config/config.go
index f8cffc3..456502a 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -122,6 +122,12 @@ func parseConfigFile(path string) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
+	// Version pragma is checked BEFORE strict parsing so users of newer
+	// features (e.g. `extends`) get an actionable "upgrade required"
+	// error instead of a raw yaml `field ... not found` message.
+	if err := enforceRequiresComment(path, data); err != nil {
+		return nil, err
+	}
 	return parseConfigBytes(data, filepath.Ext(path))
 }
 
diff --git a/internal/config/merge.go b/internal/config/merge.go
index 52553bf..10dfbc7 100644
--- a/internal/config/merge.go
+++ b/internal/config/merge.go
@@ -21,6 +21,29 @@ var presetNames = map[string]string{
 	"generic":         "presets/generic.yaml",
 }
 
+// ReadPreset returns the raw YAML bytes of a preset by name (as it would
+// appear in `extends:`). Exposed for `structlint init` so the four
+// project templates are stored in one place instead of duplicated as
+// Go string literals in internal/cli/init.go.
+func ReadPreset(name string) ([]byte, error) {
+	path, ok := presetNames[name]
+	if !ok {
+		return nil, fmt.Errorf("unknown preset %q (valid: %s)", name, presetsList())
+	}
+	return presetFS.ReadFile(path)
+}
+
+// PresetNames returns the sorted list of built-in preset names for
+// error messages and completion.
+func PresetNames() []string {
+	out := make([]string, 0, len(presetNames))
+	for name := range presetNames {
+		out = append(out, name)
+	}
+	sort.Strings(out)
+	return out
+}
+
 const maxExtendsDepth = 10
 
 // loadResolved parses path, resolves its extends chain depth-first with
diff --git a/internal/config/versioncheck.go b/internal/config/versioncheck.go
new file mode 100644
index 0000000..3a02d03
--- /dev/null
+++ b/internal/config/versioncheck.go
@@ -0,0 +1,111 @@
+package config
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/AxeForging/structlint/internal/build"
+)
+
+// requiresRE matches a `# requires structlint >= vX.Y[.Z]` comment
+// anywhere in the config file. Whitespace around tokens is tolerated;
+// the version literal is left unquoted, in vX.Y or vX.Y.Z form.
+var requiresRE = regexp.MustCompile(`(?m)^\s*#\s*requires\s+structlint\s*>=\s*v?(\d+)\.(\d+)(?:\.(\d+))?`)
+
+// enforceRequiresComment inspects raw config bytes for a version pragma
+// and fails with a helpful message when the running binary is older than
+// the required version. Skips when the running binary is a dev build —
+// unstamped local builds can't be meaningfully compared to a tag.
+func enforceRequiresComment(configPath string, data []byte) error {
+	match := requiresRE.FindSubmatch(data)
+	if match == nil {
+		return nil
+	}
+	need, err := parseSemver(string(match[1]), string(match[2]), string(match[3]))
+	if err != nil {
+		return nil // malformed comment; ignore
+	}
+	current, ok := parseBinaryVersion(build.Version)
+	if !ok {
+		// dev build or otherwise unparseable; don't second-guess it.
+		return nil
+	}
+	if semverLess(current, need) {
+		return fmt.Errorf(
+			"%s requires structlint >= v%s, but running version is v%s.\n"+
+				"Upgrade the binary (go install github.com/AxeForging/structlint/cmd/structlint@latest) "+
+				"or pin the older feature set by removing the pragma.",
+			configPath, semverString(need), semverString(current),
+		)
+	}
+	return nil
+}
+
+type semver struct{ Major, Minor, Patch int }
+
+func parseSemver(major, minor, patch string) (semver, error) {
+	M, err := strconv.Atoi(major)
+	if err != nil {
+		return semver{}, err
+	}
+	m, err := strconv.Atoi(minor)
+	if err != nil {
+		return semver{}, err
+	}
+	p := 0
+	if patch != "" {
+		p, err = strconv.Atoi(patch)
+		if err != nil {
+			return semver{}, err
+		}
+	}
+	return semver{Major: M, Minor: m, Patch: p}, nil
+}
+
+// parseBinaryVersion extracts a semver from build.Version. Accepts the
+// leading `v`, tolerates trailing metadata (e.g. `v0.6.0-3-gabcdef-dirty`
+// or `v0.6.0+meta`). Returns ok=false for `dev` or unparseable inputs so
+// callers can skip the check.
+func parseBinaryVersion(v string) (semver, bool) {
+	v = strings.TrimSpace(v)
+	if v == "" || v == "dev" || v == "unknown" {
+		return semver{}, false
+	}
+	v = strings.TrimPrefix(v, "v")
+	// Split on the first hyphen or plus so metadata like `-3-gabc-dirty` or
+	// `+meta` doesn't confuse the parse.
+	for _, sep := range []string{"-", "+"} {
+		if idx := strings.Index(v, sep); idx > 0 {
+			v = v[:idx]
+		}
+	}
+	parts := strings.Split(v, ".")
+	if len(parts) < 2 {
+		return semver{}, false
+	}
+	patch := "0"
+	if len(parts) >= 3 {
+		patch = parts[2]
+	}
+	sv, err := parseSemver(parts[0], parts[1], patch)
+	if err != nil {
+		return semver{}, false
+	}
+	return sv, true
+}
+
+func semverLess(a, b semver) bool {
+	if a.Major != b.Major {
+		return a.Major < b.Major
+	}
+	if a.Minor != b.Minor {
+		return a.Minor < b.Minor
+	}
+	return a.Patch < b.Patch
+}
+
+func semverString(s semver) string {
+	return fmt.Sprintf("%d.%d.%d", s.Major, s.Minor, s.Patch)
+}
diff --git a/internal/config/versioncheck_test.go b/internal/config/versioncheck_test.go
new file mode 100644
index 0000000..ac22dee
--- /dev/null
+++ b/internal/config/versioncheck_test.go
@@ -0,0 +1,118 @@
+package config
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/AxeForging/structlint/internal/build"
+)
+
+// withBuildVersion temporarily overrides build.Version for the duration
+// of fn, restoring it via t.Cleanup so parallel tests don't leak state.
+func withBuildVersion(t *testing.T, v string) {
+	t.Helper()
+	prev := build.Version
+	build.Version = v
+	t.Cleanup(func() { build.Version = prev })
+}
+
+func TestEnforceRequiresComment_NoPragmaIsFine(t *testing.T) {
+	withBuildVersion(t, "v0.5.0")
+	err := enforceRequiresComment("test.yaml", []byte("dir_structure:\n  allowedPaths: [\".\"]\n"))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestEnforceRequiresComment_SatisfiedVersion(t *testing.T) {
+	withBuildVersion(t, "v0.6.1")
+	err := enforceRequiresComment("test.yaml", []byte(`# requires structlint >= v0.6.0
+extends: go-standard
+`))
+	if err != nil {
+		t.Fatalf("v0.6.1 should satisfy >= v0.6.0, got: %v", err)
+	}
+}
+
+func TestEnforceRequiresComment_ExactVersion(t *testing.T) {
+	withBuildVersion(t, "v0.6.0")
+	err := enforceRequiresComment("test.yaml", []byte("# requires structlint >= v0.6.0\n"))
+	if err != nil {
+		t.Fatalf("v0.6.0 should satisfy >= v0.6.0, got: %v", err)
+	}
+}
+
+func TestEnforceRequiresComment_TooOld(t *testing.T) {
+	withBuildVersion(t, "v0.5.0")
+	err := enforceRequiresComment("path.yaml", []byte("# requires structlint >= v0.6.0\n"))
+	if err == nil {
+		t.Fatal("expected error when running version is older than required")
+	}
+	msg := err.Error()
+	if !strings.Contains(msg, "requires structlint >= v0.6.0") {
+		t.Errorf("error should quote the required version, got: %s", msg)
+	}
+	if !strings.Contains(msg, "running version is v0.5.0") {
+		t.Errorf("error should quote the running version, got: %s", msg)
+	}
+	if !strings.Contains(msg, "path.yaml") {
+		t.Errorf("error should reference the config path, got: %s", msg)
+	}
+}
+
+func TestEnforceRequiresComment_DevVersionSkipsCheck(t *testing.T) {
+	withBuildVersion(t, "dev")
+	err := enforceRequiresComment("test.yaml", []byte("# requires structlint >= v99.0.0\n"))
+	if err != nil {
+		t.Fatalf("dev binary should never fail the pragma check, got: %v", err)
+	}
+}
+
+func TestEnforceRequiresComment_UnstampedDirtyVersion(t *testing.T) {
+	// Build metadata (e.g. `-3-gabcdef-dirty`) should not confuse the check.
+	withBuildVersion(t, "v0.6.0-3-gabcdef-dirty")
+	err := enforceRequiresComment("test.yaml", []byte("# requires structlint >= v0.6.0\n"))
+	if err != nil {
+		t.Fatalf("v0.6.0-with-metadata should satisfy >= v0.6.0, got: %v", err)
+	}
+}
+
+func TestEnforceRequiresComment_MinorVersionOnly(t *testing.T) {
+	// Pragma without patch should still work.
+	withBuildVersion(t, "v0.5.9")
+	err := enforceRequiresComment("test.yaml", []byte("# requires structlint >= v0.6\n"))
+	if err == nil {
+		t.Fatal("expected error: v0.5.9 < v0.6.0")
+	}
+}
+
+func TestEnforceRequiresComment_MalformedPragmaIgnored(t *testing.T) {
+	withBuildVersion(t, "v0.5.0")
+	// A comment mentioning the phrase but with garbage version → tolerate.
+	err := enforceRequiresComment("test.yaml", []byte("# structlint is a linter\n"))
+	if err != nil {
+		t.Fatalf("comment without a real pragma should not error: %v", err)
+	}
+}
+
+func TestParseBinaryVersion_DevBuild(t *testing.T) {
+	if _, ok := parseBinaryVersion("dev"); ok {
+		t.Error("dev version must return ok=false")
+	}
+	if _, ok := parseBinaryVersion(""); ok {
+		t.Error("empty version must return ok=false")
+	}
+	if _, ok := parseBinaryVersion("unknown"); ok {
+		t.Error("unknown version must return ok=false")
+	}
+}
+
+func TestParseBinaryVersion_WithMetadata(t *testing.T) {
+	sv, ok := parseBinaryVersion("v1.2.3-rc.1")
+	if !ok {
+		t.Fatal("expected parse to succeed")
+	}
+	if sv.Major != 1 || sv.Minor != 2 || sv.Patch != 3 {
+		t.Errorf("got %+v, want 1.2.3", sv)
+	}
+}
diff --git a/internal/validator/engine.go b/internal/validator/engine.go
index 7566847..8bbaa9d 100644
--- a/internal/validator/engine.go
+++ b/internal/validator/engine.go
@@ -1,11 +1,17 @@
 package validator
 
-import "github.com/AxeForging/structlint/internal/config"
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/AxeForging/structlint/internal/config"
+)
 
 // Rule is the pluggable unit of validation. Each family (dir structure,
-// file naming, placement, ...) is a Rule. Rules run in the order Registry
-// returns them; that order matches the legacy Validate* invocation
-// sequence and is part of the observable contract (spec 005).
+// file naming, placement, ...) is a Rule. Rules run in Registry order —
+// that order matches the legacy Validate* invocation sequence and is
+// part of the observable contract enforced by the parity goldens.
 type Rule interface {
 	Name() string
 	Run(ctx *RunContext)
@@ -18,14 +24,13 @@ type RunContext struct {
 	V    *Validator
 	// Skip returns true when the given relative path (dir or file) is out
 	// of scope for --changed-only / --staged. Rules that are meant to be
-	// global (required-* families) do not consult Skip.
+	// global (required-* families) never call Skip.
 	Skip func(relPath string, isDir bool) bool
 }
 
 // Registry returns the seven rules in legacy execution order:
 // dir_structure, file_naming, required_paths, required_files,
-// placement, required_groups, boundaries. Spec 010's suggest command
-// enumerates rules through this registry.
+// placement, required_groups, boundaries.
 func Registry(cfg *config.Config) []Rule {
 	return []Rule{
 		dirStructureRule{},
@@ -39,8 +44,8 @@ func Registry(cfg *config.Config) []Rule {
 }
 
 // Run snapshots the tree once, then executes each rule in Registry order
-// against the same snapshot. Wire from validate.go instead of calling the
-// seven Validate* methods individually.
+// against that single snapshot. This is the single-walk architecture:
+// rules do not perform their own filepath.Walk — they iterate ctx.Tree.
 func (v *Validator) Run(path string) {
 	tree := Snapshot(path, v.Config.Ignore)
 	ctx := &RunContext{
@@ -59,57 +64,260 @@ func (v *Validator) Run(path string) {
 	}
 }
 
-// The seven rule types below are thin wrappers around the existing
-// Validate* method bodies. They call the legacy method, which walks the
-// tree itself. Consolidating the walks is a follow-up refactor (see spec
-// 005's non-goals); this iteration lands the enumerable Registry / Tree
-// surface that specs 009 and 010 depend on without touching output.
+// skipTracker tracks path prefixes whose subtree should be skipped from
+// iteration. Used to preserve filepath.SkipDir semantics when we hit a
+// disallowed directory in the middle of a single walk.
+type skipTracker struct {
+	prefixes []string
+}
+
+// mark adds relPath as the root of a skipped subtree.
+func (s *skipTracker) mark(relPath string) {
+	if relPath == "" || relPath == "." {
+		return
+	}
+	s.prefixes = append(s.prefixes, relPath)
+}
 
+// under reports whether relPath is inside any skipped subtree.
+func (s *skipTracker) under(relPath string) bool {
+	for _, p := range s.prefixes {
+		if relPath == p || strings.HasPrefix(relPath, p+"/") {
+			return true
+		}
+	}
+	return false
+}
+
+// dirStructureRule validates directory structure by iterating Tree.Entries.
+// Preserves filepath.SkipDir semantics: hitting a disallowed directory
+// suppresses violations for its entire subtree (matching the legacy walk).
 type dirStructureRule struct{}
 
 func (dirStructureRule) Name() string { return "dir_structure" }
+
 func (dirStructureRule) Run(ctx *RunContext) {
-	ctx.V.ValidateDirStructure(ctx.Tree.Root)
+	if ctx.Tree.WalkErr != nil {
+		ctx.V.addViolation("walk_error", "error", ctx.Tree.Root, "filesystem",
+			fmt.Sprintf("Error walking directory: %s", ctx.Tree.WalkErr))
+	}
+	skipped := skipTracker{}
+	for _, e := range ctx.Tree.Entries {
+		if !e.IsDir {
+			continue
+		}
+		if skipped.under(e.RelPath) {
+			continue
+		}
+		if ctx.Skip(e.RelPath, true) {
+			// Not part of the changed-set; skip its subtree too, matching
+			// the legacy behavior where the walker returned SkipDir.
+			skipped.mark(e.RelPath)
+			continue
+		}
+		// Check against disallowed paths.
+		matched := false
+		for _, disallowed := range ctx.Cfg.DirStructure.DisallowedPaths {
+			if pathMatches(e.RelPath, disallowed) {
+				msg := fmt.Sprintf("Disallowed directory found: %s", e.RelPath)
+				ctx.V.addViolation("disallowed_directory", "error", e.RelPath, disallowed, msg)
+				skipped.mark(e.RelPath)
+				matched = true
+				break
+			}
+		}
+		if matched {
+			continue
+		}
+		// Check against allowed paths.
+		isAllowed := false
+		for _, allowed := range ctx.Cfg.DirStructure.AllowedPaths {
+			if pathMatches(e.RelPath, allowed) || isParentOfPattern(e.RelPath, allowed) {
+				isAllowed = true
+				break
+			}
+		}
+		if isAllowed {
+			ctx.V.printSuccess(fmt.Sprintf("Allowed directory found: %s", e.RelPath))
+			ctx.V.Successes++
+		} else {
+			msg := fmt.Sprintf("Directory not in allowed list: %s", e.RelPath)
+			ctx.V.addViolation("unallowed_directory", "error", e.RelPath, "dir_structure.allowedPaths", msg)
+		}
+	}
 }
 
+// fileNamingRule validates file naming patterns via Tree iteration.
 type fileNamingRule struct{}
 
 func (fileNamingRule) Name() string { return "file_naming" }
+
 func (fileNamingRule) Run(ctx *RunContext) {
-	ctx.V.ValidateFileNaming(ctx.Tree.Root)
+	if ctx.Tree.WalkErr != nil {
+		ctx.V.addViolation("walk_error", "error", ctx.Tree.Root, "filesystem",
+			fmt.Sprintf("Error walking directory: %s", ctx.Tree.WalkErr))
+	}
+	for _, e := range ctx.Tree.Entries {
+		if e.IsDir {
+			continue
+		}
+		if ctx.Skip(e.RelPath, false) {
+			continue
+		}
+		// Disallowed patterns first — matching a disallowed pattern short-
+		// circuits, matching legacy behavior of `return nil`.
+		matched := false
+		for _, disallowed := range ctx.Cfg.FileNamingPattern.Disallowed {
+			if pathMatches(e.Name, disallowed) || pathMatches(e.RelPath, disallowed) {
+				msg := fmt.Sprintf("Disallowed file naming pattern found: %s", e.RelPath)
+				ctx.V.addViolation("disallowed_file_pattern", "error", e.RelPath, disallowed, msg)
+				matched = true
+				break
+			}
+		}
+		if matched {
+			continue
+		}
+		isAllowed := false
+		for _, allowed := range ctx.Cfg.FileNamingPattern.Allowed {
+			if pathMatches(e.Name, allowed) || pathMatches(e.RelPath, allowed) {
+				isAllowed = true
+				break
+			}
+		}
+		if isAllowed {
+			ctx.V.printSuccess(fmt.Sprintf("Allowed file naming pattern found: %s", e.RelPath))
+			ctx.V.Successes++
+		} else {
+			msg := fmt.Sprintf("File not in allowed naming pattern: %s", e.RelPath)
+			ctx.V.addViolation("unallowed_file_pattern", "error", e.RelPath, "file_naming_pattern.allowed", msg)
+		}
+	}
 }
 
+// requiredPathsRule intentionally does NOT use the Tree — the legacy code
+// stats the joined path directly, so a required path inside an ignored
+// directory still counts as present. Preserving that quirk is spec 005's
+// parity requirement.
 type requiredPathsRule struct{}
 
 func (requiredPathsRule) Name() string { return "required_paths" }
+
 func (requiredPathsRule) Run(ctx *RunContext) {
-	ctx.V.ValidateRequiredPaths(ctx.Tree.Root)
+	ctx.V.validateRequiredPathsDirect(ctx.Tree.Root)
 }
 
+// requiredFilesRule finds required patterns via Tree lookup. Unlike required
+// paths, the legacy code walked with ignore filtering, so using the Tree
+// matches behavior.
 type requiredFilesRule struct{}
 
 func (requiredFilesRule) Name() string { return "required_files" }
+
 func (requiredFilesRule) Run(ctx *RunContext) {
-	ctx.V.ValidateRequiredFiles(ctx.Tree.Root)
+	for _, requiredFile := range ctx.Cfg.FileNamingPattern.Required {
+		found := false
+		for _, e := range ctx.Tree.Entries {
+			if e.IsDir {
+				continue
+			}
+			if pathMatches(e.Name, requiredFile) || pathMatches(e.RelPath, requiredFile) {
+				found = true
+				break
+			}
+		}
+		if found {
+			ctx.V.printSuccess(fmt.Sprintf("Required file pattern found: %s", requiredFile))
+			ctx.V.Successes++
+		} else {
+			msg := fmt.Sprintf("Required file pattern missing: %s", requiredFile)
+			ctx.V.addViolation("missing_required_file", "error", requiredFile, requiredFile, msg)
+		}
+	}
 }
 
+// placementRule iterates Tree files and applies placement rules. Preserves
+// the counter quirk from the legacy walk: v.Successes++ is called for
+// every (file, rule) pair that passes — a file matching N placement rules
+// contributes N successes.
 type placementRule struct{}
 
 func (placementRule) Name() string { return "placement" }
+
 func (placementRule) Run(ctx *RunContext) {
-	ctx.V.ValidatePlacement(ctx.Tree.Root)
+	for _, e := range ctx.Tree.Entries {
+		if e.IsDir {
+			continue
+		}
+		if ctx.Skip(e.RelPath, false) {
+			continue
+		}
+		for _, rule := range ctx.Cfg.Placement {
+			if !matchesAnyFile(e.RelPath, e.Name, rule.Files) {
+				continue
+			}
+			if underAny(e.RelPath, rule.MustBeUnder) {
+				ctx.V.Successes++
+				continue
+			}
+			msg := fmt.Sprintf("File placement violation: %s must be under %s",
+				e.RelPath, strings.Join(rule.MustBeUnder, ", "))
+			ctx.V.addViolation("placement_violation", severity(rule.Severity), e.RelPath, rule.ID, msg)
+		}
+	}
 }
 
+// requiredGroupsRule uses stat-based helpers (existsAt, existsAny,
+// matchingDirs) which look through ignored directories on purpose — same
+// quirk as requiredPathsRule.
 type requiredGroupsRule struct{}
 
 func (requiredGroupsRule) Name() string { return "required_groups" }
+
 func (requiredGroupsRule) Run(ctx *RunContext) {
-	ctx.V.ValidateRequiredGroups(ctx.Tree.Root)
+	ctx.V.validateRequiredGroupsDirect(ctx.Tree.Root)
 }
 
+// boundariesRule iterates supported source files in the Tree, parses
+// imports, and reports violations. Preserves the counter quirk: Successes++
+// is incremented once per (file, matching rule) pair even when that pair
+// produced boundary violations, matching legacy behavior.
 type boundariesRule struct{}
 
 func (boundariesRule) Name() string { return "boundaries" }
+
 func (boundariesRule) Run(ctx *RunContext) {
-	ctx.V.ValidateBoundaries(ctx.Tree.Root)
+	modulePath := readGoModule(ctx.Tree.Root)
+	for _, e := range ctx.Tree.Entries {
+		if e.IsDir {
+			continue
+		}
+		if !isSupportedBoundaryFile(e.RelPath) {
+			continue
+		}
+		if ctx.Skip(e.RelPath, false) {
+			continue
+		}
+		for _, rule := range ctx.Cfg.Boundaries {
+			if !pathMatches(e.RelPath, rule.From) {
+				continue
+			}
+			imports, err := sourceImports(filepath.Join(ctx.Tree.Root, e.RelPath), e.RelPath)
+			if err != nil {
+				ctx.V.addViolation("parse_error", "error", e.RelPath, rule.ID,
+					fmt.Sprintf("Failed to parse imports: %s", err))
+				continue
+			}
+			for _, imp := range imports {
+				localImport := importToLocalPath(modulePath, imp, e.RelPath)
+				for _, forbidden := range rule.CannotImport {
+					if pathMatches(imp, forbidden) || pathMatches(localImport, forbidden) {
+						msg := fmt.Sprintf("Boundary violation: %s imports %s", e.RelPath, imp)
+						ctx.V.addViolation("boundary_violation", severity(rule.Severity), e.RelPath, rule.ID, msg)
+					}
+				}
+			}
+			ctx.V.Successes++
+		}
+	}
 }
diff --git a/internal/validator/validator.go b/internal/validator/validator.go
index 049fbad..1386ddd 100644
--- a/internal/validator/validator.go
+++ b/internal/validator/validator.go
@@ -43,62 +43,30 @@ func New(cfg *config.Config, logger *slog.Logger) *Validator {
 	}
 }
 
-// ValidateDirStructure validates the directory structure.
+// ValidateDirStructure is a thin wrapper kept for external callers (e.g. the
+// root validator_test.go). It snapshots the tree and runs the corresponding
+// rule against it — same output as v.Run() would produce.
 func (v *Validator) ValidateDirStructure(path string) {
-	root := cleanRoot(path)
-	err := filepath.Walk(path, func(currentPath string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		relPath := relativePath(root, currentPath)
-
-		// Check if the path should be ignored
-		for _, ignored := range v.Config.Ignore {
-			if pathMatches(relPath, ignored) {
-				if info.IsDir() {
-					return filepath.SkipDir
-				}
-				return nil
-			}
-		}
-
-		if info.IsDir() {
-			if v.shouldSkipChangedDir(relPath) {
-				return filepath.SkipDir
-			}
-
-			// Check against disallowed paths
-			for _, disallowed := range v.Config.DirStructure.DisallowedPaths {
-				if pathMatches(relPath, disallowed) {
-					msg := fmt.Sprintf("Disallowed directory found: %s", relPath)
-					v.addViolation("disallowed_directory", "error", relPath, disallowed, msg)
-					return filepath.SkipDir // Skip validating contents of disallowed directories
-				}
-			}
-
-			// Check against allowed paths
-			isAllowed := false
-			for _, allowed := range v.Config.DirStructure.AllowedPaths {
-				if pathMatches(relPath, allowed) || isParentOfPattern(relPath, allowed) {
-					isAllowed = true
-					break
-				}
-			}
+	v.runSingleRule(path, dirStructureRule{})
+}
 
-			if isAllowed {
-				msg := fmt.Sprintf("Allowed directory found: %s", relPath)
-				v.printSuccess(msg)
-				v.Successes++
-			} else {
-				msg := fmt.Sprintf("Directory not in allowed list: %s", relPath)
-				v.addViolation("unallowed_directory", "error", relPath, "dir_structure.allowedPaths", msg)
+// runSingleRule is the shared entry point for the legacy Validate* wrappers.
+// It snapshots root once and runs exactly one rule so wrapper behavior
+// stays parity-safe with the modern v.Run() path.
+func (v *Validator) runSingleRule(path string, rule Rule) {
+	tree := Snapshot(path, v.Config.Ignore)
+	ctx := &RunContext{
+		Cfg:  v.Config,
+		Tree: tree,
+		V:    v,
+		Skip: func(rel string, isDir bool) bool {
+			if isDir {
+				return v.shouldSkipChangedDir(rel)
 			}
-		}
-		return nil
-	})
-	if err != nil {
-		v.addViolation("walk_error", "error", path, "filesystem", fmt.Sprintf("Error walking directory: %s", err))
+			return v.shouldSkipChanged(rel)
+		},
 	}
+	rule.Run(ctx)
 }
 
 // matches checks if a path matches a glob pattern.
@@ -110,62 +78,9 @@ func matches(path, pattern string) bool {
 	return g.Match(path)
 }
 
-// ValidateFileNaming validates the file naming conventions.
+// ValidateFileNaming is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidateFileNaming(path string) {
-	root := cleanRoot(path)
-	err := filepath.Walk(path, func(currentPath string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		relPath := relativePath(root, currentPath)
-
-		// Check if the path should be ignored
-		for _, ignored := range v.Config.Ignore {
-			if pathMatches(relPath, ignored) {
-				if info.IsDir() {
-					return filepath.SkipDir
-				}
-				return nil
-			}
-		}
-
-		if !info.IsDir() {
-			if v.shouldSkipChanged(relPath) {
-				return nil
-			}
-			fileName := info.Name()
-
-			// Check against disallowed patterns
-			for _, disallowed := range v.Config.FileNamingPattern.Disallowed {
-				if pathMatches(fileName, disallowed) || pathMatches(relPath, disallowed) {
-					msg := fmt.Sprintf("Disallowed file naming pattern found: %s", relPath)
-					v.addViolation("disallowed_file_pattern", "error", relPath, disallowed, msg)
-					return nil
-				}
-			}
-
-			// Check against allowed patterns
-			isAllowed := false
-			for _, allowed := range v.Config.FileNamingPattern.Allowed {
-				if pathMatches(fileName, allowed) || pathMatches(relPath, allowed) {
-					isAllowed = true
-					break
-				}
-			}
-			if isAllowed {
-				msg := fmt.Sprintf("Allowed file naming pattern found: %s", relPath)
-				v.printSuccess(msg)
-				v.Successes++
-			} else {
-				msg := fmt.Sprintf("File not in allowed naming pattern: %s", relPath)
-				v.addViolation("unallowed_file_pattern", "error", relPath, "file_naming_pattern.allowed", msg)
-			}
-		}
-		return nil
-	})
-	if err != nil {
-		v.addViolation("walk_error", "error", path, "filesystem", fmt.Sprintf("Error walking directory: %s", err))
-	}
+	v.runSingleRule(path, fileNamingRule{})
 }
 
 // PrintSummary prints a summary of the validation results.
@@ -197,12 +112,17 @@ func (v *Validator) PrintSummary() {
 	}
 }
 
-// ValidateRequiredPaths validates that all required directories exist.
+// ValidateRequiredPaths is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidateRequiredPaths(path string) {
+	v.validateRequiredPathsDirect(path)
+}
+
+// validateRequiredPathsDirect stats each requiredPath directly. Preserves
+// the quirk that requiredPaths inside an ignored directory still count
+// as present — this is the legacy behavior locked by parity goldens.
+func (v *Validator) validateRequiredPathsDirect(path string) {
 	for _, requiredPath := range v.Config.DirStructure.RequiredPaths {
 		fullPath := filepath.Join(path, requiredPath)
-
-		// Check if the required path exists
 		if _, err := os.Stat(fullPath); os.IsNotExist(err) {
 			msg := fmt.Sprintf("Required directory missing: %s", requiredPath)
 			v.addViolation("missing_required_directory", "error", requiredPath, "dir_structure.requiredPaths", msg)
@@ -213,91 +133,26 @@ func (v *Validator) ValidateRequiredPaths(path string) {
 	}
 }
 
-// ValidateRequiredFiles validates that all required files exist.
+// ValidateRequiredFiles is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidateRequiredFiles(path string) {
-	root := cleanRoot(path)
-	for _, requiredFile := range v.Config.FileNamingPattern.Required {
-		// Check if any file matching the pattern exists
-		found := false
-		err := filepath.Walk(path, func(currentPath string, info os.FileInfo, err error) error {
-			if err != nil {
-				return err
-			}
-			relPath := relativePath(root, currentPath)
-
-			// Check if the path should be ignored
-			for _, ignored := range v.Config.Ignore {
-				if pathMatches(relPath, ignored) {
-					if info.IsDir() {
-						return filepath.SkipDir
-					}
-					return nil
-				}
-			}
-
-			if !info.IsDir() {
-				// For required file patterns, we need to check both the filename and the relative path
-				fileName := info.Name()
-				// Check if either the filename or the relative path matches the pattern
-				if pathMatches(fileName, requiredFile) || pathMatches(relPath, requiredFile) {
-					found = true
-					return filepath.SkipAll // Stop walking once we find a match
-				}
-			}
-			return nil
-		})
-		if err != nil {
-			v.addViolation("walk_error", "error", requiredFile, "file_naming_pattern.required", fmt.Sprintf("Error checking for required file %s: %s", requiredFile, err))
-			continue
-		}
-
-		if found {
-			v.printSuccess(fmt.Sprintf("Required file pattern found: %s", requiredFile))
-			v.Successes++
-		} else {
-			msg := fmt.Sprintf("Required file pattern missing: %s", requiredFile)
-			v.addViolation("missing_required_file", "error", requiredFile, requiredFile, msg)
-		}
-	}
+	v.runSingleRule(path, requiredFilesRule{})
 }
 
-// ValidatePlacement validates file placement rules.
+// ValidatePlacement is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidatePlacement(path string) {
-	root := cleanRoot(path)
-	_ = filepath.Walk(path, func(currentPath string, info os.FileInfo, err error) error {
-		if err != nil {
-			v.addViolation("walk_error", "error", currentPath, "placement", fmt.Sprintf("Error walking directory: %s", err))
-			return nil
-		}
-		relPath := relativePath(root, currentPath)
-		for _, ignored := range v.Config.Ignore {
-			if pathMatches(relPath, ignored) {
-				if info.IsDir() {
-					return filepath.SkipDir
-				}
-				return nil
-			}
-		}
-		if info.IsDir() || v.shouldSkipChanged(relPath) {
-			return nil
-		}
-		for _, rule := range v.Config.Placement {
-			if !matchesAnyFile(relPath, info.Name(), rule.Files) {
-				continue
-			}
-			if underAny(relPath, rule.MustBeUnder) {
-				v.Successes++
-				continue
-			}
-			msg := fmt.Sprintf("File placement violation: %s must be under %s", relPath, strings.Join(rule.MustBeUnder, ", "))
-			v.addViolation("placement_violation", severity(rule.Severity), relPath, rule.ID, msg)
-		}
-		return nil
-	})
+	v.runSingleRule(path, placementRule{})
 }
 
-// ValidateRequiredGroups validates one-of and per-directory requirements.
+// ValidateRequiredGroups is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidateRequiredGroups(path string) {
+	v.validateRequiredGroupsDirect(path)
+}
+
+// validateRequiredGroupsDirect implements requiredGroups using stat-based
+// helpers (existsAt, existsAny, matchingDirs) which intentionally see
+// through ignored directories. Preserving that behavior is a parity
+// requirement locked by the goldens.
+func (v *Validator) validateRequiredGroupsDirect(path string) {
 	root := cleanRoot(path)
 	for _, group := range v.Config.RequiredGroups {
 		if len(group.OneOf) > 0 {
@@ -344,49 +199,9 @@ func (v *Validator) ValidateRequiredGroups(path string) {
 	}
 }
 
-// ValidateBoundaries validates import boundaries for supported source files.
+// ValidateBoundaries is a thin wrapper — see runSingleRule.
 func (v *Validator) ValidateBoundaries(path string) {
-	root := cleanRoot(path)
-	modulePath := readGoModule(root)
-	_ = filepath.Walk(path, func(currentPath string, info os.FileInfo, err error) error {
-		if err != nil {
-			v.addViolation("walk_error", "error", currentPath, "boundaries", fmt.Sprintf("Error walking directory: %s", err))
-			return nil
-		}
-		relPath := relativePath(root, currentPath)
-		for _, ignored := range v.Config.Ignore {
-			if pathMatches(relPath, ignored) {
-				if info.IsDir() {
-					return filepath.SkipDir
-				}
-				return nil
-			}
-		}
-		if info.IsDir() || !isSupportedBoundaryFile(relPath) || v.shouldSkipChanged(relPath) {
-			return nil
-		}
-		for _, rule := range v.Config.Boundaries {
-			if !pathMatches(relPath, rule.From) {
-				continue
-			}
-			imports, err := sourceImports(currentPath, relPath)
-			if err != nil {
-				v.addViolation("parse_error", "error", relPath, rule.ID, fmt.Sprintf("Failed to parse imports: %s", err))
-				continue
-			}
-			for _, imp := range imports {
-				localImport := importToLocalPath(modulePath, imp, relPath)
-				for _, forbidden := range rule.CannotImport {
-					if pathMatches(imp, forbidden) || pathMatches(localImport, forbidden) {
-						msg := fmt.Sprintf("Boundary violation: %s imports %s", relPath, imp)
-						v.addViolation("boundary_violation", severity(rule.Severity), relPath, rule.ID, msg)
-					}
-				}
-			}
-			v.Successes++
-		}
-		return nil
-	})
+	v.runSingleRule(path, boundariesRule{})
 }
 
 // LoadChangedPaths populates the changed-file set used by --changed-only,
diff --git a/test/init_presets_test.go b/test/init_presets_test.go
new file mode 100644
index 0000000..a7fc275
--- /dev/null
+++ b/test/init_presets_test.go
@@ -0,0 +1,91 @@
+package test
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// TestInitTypeUsesPresetBody asserts that `init --type <T>` writes a file
+// whose body (below the header comment) is byte-identical to the embedded
+// preset that `extends: <T>-standard` (or `generic`) resolves to.
+// This locks in the deduplication of spec 007's presets and init's
+// templates — they were duplicated string literals before this refactor.
+func TestInitTypeUsesPresetBody(t *testing.T) {
+	bin := buildBinary(t)
+
+	cases := map[string]string{
+		"go":      "go-standard.yaml",
+		"node":    "node-standard.yaml",
+		"python":  "python-standard.yaml",
+		"generic": "generic.yaml",
+	}
+
+	for typ, presetFile := range cases {
+		t.Run(typ, func(t *testing.T) {
+			dir := t.TempDir()
+			if out, err := runBinaryInDir(t, bin, dir, "init", "--type", typ); err != nil {
+				t.Fatalf("init --type %s: %v\n%s", typ, err, out)
+			}
+			generated := readFile(t, filepath.Join(dir, ".structlint.yaml"))
+
+			// Strip the first line (the header comment) — the rest must
+			// match the preset byte-for-byte.
+			nl := strings.Index(generated, "\n")
+			if nl < 0 {
+				t.Fatalf("generated config has no newline: %q", generated)
+			}
+			body := generated[nl+1:]
+
+			presetPath := filepath.Join(repoRoot(t), "internal", "config", "presets", presetFile)
+			presetData, err := os.ReadFile(presetPath)
+			if err != nil {
+				t.Fatalf("read preset %s: %v", presetPath, err)
+			}
+			if body != string(presetData) {
+				t.Errorf("init --type %s body drifted from preset %s\n--- got body ---\n%s\n--- preset ---\n%s",
+					typ, presetFile, body, string(presetData))
+			}
+		})
+	}
+}
+
+// TestInitTypeAndExtendsProduceEquivalentValidation is the semantic
+// twin of the byte test above: init --type <T> and a config with
+// `extends: <T>-standard` should validate the same tree the same way.
+func TestInitTypeAndExtendsProduceEquivalentValidation(t *testing.T) {
+	bin := buildBinary(t)
+
+	// Minimal go-shaped project the go-standard preset would pass on.
+	files := map[string]string{
+		"go.mod":            "module t\n",
+		"README.md":         "# t\n",
+		".gitignore":        "bin/\n",
+		"cmd/app/main.go":   "package main\n\nfunc main() {}\n",
+		"internal/foo/x.go": "package foo\n",
+	}
+
+	// init --type go path.
+	dirA := t.TempDir()
+	for p, content := range files {
+		writeTestFile(t, dirA, p, content)
+	}
+	if out, err := runBinaryInDir(t, bin, dirA, "init", "--type", "go", "--force"); err != nil {
+		t.Fatalf("init: %v\n%s", err, out)
+	}
+	outA, errA := runBinaryInDir(t, bin, dirA, "validate", "--silent")
+
+	// extends: go-standard path.
+	dirB := t.TempDir()
+	for p, content := range files {
+		writeTestFile(t, dirB, p, content)
+	}
+	writeTestFile(t, dirB, ".structlint.yaml", "extends: go-standard\n")
+	outB, errB := runBinaryInDir(t, bin, dirB, "validate", "--silent")
+
+	if (errA == nil) != (errB == nil) {
+		t.Errorf("validation outcomes diverge:\n  init --type go: err=%v\n  extends: go-standard: err=%v\n\n  outA=%s\n  outB=%s",
+			errA, errB, outA, outB)
+	}
+}
diff --git a/test/skill_deep_test.go b/test/skill_deep_test.go
new file mode 100644
index 0000000..fd14907
--- /dev/null
+++ b/test/skill_deep_test.go
@@ -0,0 +1,194 @@
+package test
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/AxeForging/structlint/internal/app"
+	"github.com/AxeForging/structlint/internal/validator"
+	"gopkg.in/yaml.v3"
+)
+
+// TestSkill_FrontmatterParsesAsYAML asserts SKILL.md's frontmatter is
+// valid YAML (agents load it via a YAML parser) and declares the fields
+// their runtime keys on.
+func TestSkill_FrontmatterParsesAsYAML(t *testing.T) {
+	body := readSkillFile(t)
+	front := extractFrontmatter(t, body)
+
+	var meta struct {
+		Name        string `yaml:"name"`
+		Description string `yaml:"description"`
+	}
+	if err := yaml.Unmarshal([]byte(front), &meta); err != nil {
+		t.Fatalf("SKILL.md frontmatter is not valid YAML: %v\n%s", err, front)
+	}
+	if meta.Name != "structlint" {
+		t.Errorf("expected name: structlint, got %q", meta.Name)
+	}
+	if len(strings.TrimSpace(meta.Description)) < 30 {
+		t.Errorf("description is too short to be useful (agents key on it): %q", meta.Description)
+	}
+}
+
+// TestSkill_FrontmatterHasTriggerPhrases asserts the description contains
+// concrete trigger phrases so agent runtimes match user requests to this
+// skill. Parses the YAML first so block-scalar folded newlines don't
+// hide multi-word phrases.
+func TestSkill_FrontmatterHasTriggerPhrases(t *testing.T) {
+	body := readSkillFile(t)
+	front := extractFrontmatter(t, body)
+	var meta struct {
+		Description string `yaml:"description"`
+	}
+	if err := yaml.Unmarshal([]byte(front), &meta); err != nil {
+		t.Fatalf("parse frontmatter: %v", err)
+	}
+	// Collapse whitespace before searching: block scalars fold newlines
+	// to a single space, but leading indentation could still trip us up
+	// if the layout changes. Normalize aggressively.
+	desc := strings.Join(strings.Fields(meta.Description), " ")
+
+	phrases := []string{
+		"structlint violation",
+		"where should this file go",
+		"enforce directory layout",
+		"file in the wrong place",
+	}
+	for _, phrase := range phrases {
+		if !strings.Contains(desc, phrase) {
+			t.Errorf("SKILL.md description missing trigger phrase %q", phrase)
+		}
+	}
+}
+
+// TestSkill_CoversAllViolationCodes cross-checks both directions — every
+// code in the CodeDescriptions registry appears in the SKILL.md table
+// AND every code in the SKILL.md table is a real registry entry.
+func TestSkill_CoversAllViolationCodes(t *testing.T) {
+	body := readSkillFile(t)
+
+	// Registry → doc.
+	for code := range validator.CodeDescriptions {
+		if !strings.Contains(body, "`"+code+"`") {
+			t.Errorf("SKILL.md missing code %q from decision table", code)
+		}
+	}
+
+	// Doc → registry. Codes appear in table cells as `code_name` — greedy
+	// enough regex; false positives (e.g. code lookalikes in prose) are
+	// tolerated. What we want to catch is stale renames.
+	re := regexp.MustCompile("`([a-z_]+_[a-z_]+)`")
+	matches := re.FindAllStringSubmatch(body, -1)
+	seen := map[string]bool{}
+	for _, m := range matches {
+		token := m[1]
+		if seen[token] {
+			continue
+		}
+		seen[token] = true
+		if _, ok := validator.CodeDescriptions[token]; ok {
+			continue
+		}
+		// Whitelist tokens that look like codes but are structlint concepts
+		// or config fields discussed in the skill.
+		if isSkillConcept(token) {
+			continue
+		}
+		// Whitelist standard shell/config words that pattern-match the
+		// underscore convention but aren't codes.
+		t.Logf("hint: %q looks like a code in SKILL.md but isn't in the registry (typo?)", token)
+	}
+}
+
+// TestSkill_ReferencedCommandsExist boots the CLI in-process and asserts
+// that every subcommand the SKILL.md setup recipes tell the agent to
+// run is a real registered command. Catches renames of `hook install`,
+// `suggest`, etc. without doc updates.
+func TestSkill_ReferencedCommandsExist(t *testing.T) {
+	body := readSkillFile(t)
+
+	referenced := []string{
+		"validate",
+		"init",
+		"hook install",
+		"suggest",
+	}
+
+	// Route each through `--help` in-process — the CLI errors on unknown
+	// subcommands, so a passing help call proves the command is real.
+	root := app.New()
+	for _, cmd := range referenced {
+		if !strings.Contains(body, "structlint "+cmd) {
+			t.Errorf("SKILL.md never references `structlint %s` — outdated setup recipe?", cmd)
+		}
+		parts := append([]string{"structlint"}, strings.Fields(cmd)...)
+		parts = append(parts, "--help")
+		if err := root.Run(context.Background(), parts); err != nil {
+			t.Errorf("`%s` failed to boot: %v — SKILL.md references a broken subcommand path", strings.Join(parts, " "), err)
+		}
+	}
+}
+
+// TestSkill_MentionsJSONContractVersion asserts SKILL.md documents the
+// suggest JSON v1 shape (agents depend on that promise). If the version
+// bumps, the doc must bump too or agents will silently break.
+func TestSkill_MentionsJSONContractVersion(t *testing.T) {
+	body := readSkillFile(t)
+	if !strings.Contains(body, `"version": 1`) && !strings.Contains(body, "JSON v1") {
+		t.Errorf("SKILL.md does not mention the suggest JSON v1 contract shape")
+	}
+}
+
+// TestSkill_ExitCodesDocumented asserts every exit code the CLI can
+// return is mentioned. Agents shouldn't guess.
+func TestSkill_ExitCodesDocumented(t *testing.T) {
+	body := readSkillFile(t)
+	for _, code := range []string{"0", "1", "2", "3"} {
+		if !strings.Contains(body, "**"+code+"**") {
+			t.Errorf("SKILL.md doesn't call out exit code %s", code)
+		}
+	}
+}
+
+// --- helpers ---
+
+func readSkillFile(t *testing.T) string {
+	t.Helper()
+	path := filepath.Join(repoRoot(t), "skills", "structlint", "SKILL.md")
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read SKILL.md: %v", err)
+	}
+	return string(data)
+}
+
+func extractFrontmatter(t *testing.T, body string) string {
+	t.Helper()
+	if !strings.HasPrefix(body, "---\n") {
+		t.Fatalf("SKILL.md missing frontmatter delimiter")
+	}
+	rest := body[len("---\n"):]
+	end := strings.Index(rest, "\n---\n")
+	if end < 0 {
+		t.Fatalf("SKILL.md frontmatter has no closing delimiter")
+	}
+	return rest[:end]
+}
+
+// isSkillConcept whitelists tokens that pattern-match a violation-code
+// shape (snake_case with underscores) but are actually config field names,
+// commands, or other structlint concepts the skill talks about. Keeping
+// this narrow is intentional: false positives log a hint but don't fail.
+func isSkillConcept(token string) bool {
+	switch token {
+	case "dir_structure", "file_naming_pattern", "required_paths",
+		"allowed_paths", "disallowed_paths":
+		return true
+	}
+	return false
+}
diff --git a/test/testdata/parity/boundaries/.structlint.yaml b/test/testdata/parity/boundaries/.structlint.yaml
new file mode 100644
index 0000000..eb3aafb
--- /dev/null
+++ b/test/testdata/parity/boundaries/.structlint.yaml
@@ -0,0 +1,17 @@
+dir_structure:
+  allowedPaths:
+    - "."
+    - "internal/**"
+file_naming_pattern:
+  allowed:
+    - "*.go"
+    - "*.mod"
+    - "*.md"
+    - "*.yaml"
+boundaries:
+  - id: domain-no-infra
+    from: "internal/domain/**"
+    cannotImport:
+      - "internal/db/**"
+ignore:
+  - ".git"
diff --git a/test/testdata/parity/boundaries/README.md b/test/testdata/parity/boundaries/README.md
new file mode 100644
index 0000000..78e8d63
--- /dev/null
+++ b/test/testdata/parity/boundaries/README.md
@@ -0,0 +1 @@
+# boundaries
diff --git a/test/testdata/parity/boundaries/go.mod b/test/testdata/parity/boundaries/go.mod
new file mode 100644
index 0000000..b8727da
--- /dev/null
+++ b/test/testdata/parity/boundaries/go.mod
@@ -0,0 +1,3 @@
+module example.com/fixture
+
+go 1.24
diff --git a/test/testdata/parity/boundaries/internal/db/db.go b/test/testdata/parity/boundaries/internal/db/db.go
new file mode 100644
index 0000000..7851b76
--- /dev/null
+++ b/test/testdata/parity/boundaries/internal/db/db.go
@@ -0,0 +1,3 @@
+package db
+
+func Connect() string { return "conn" }
diff --git a/test/testdata/parity/boundaries/internal/domain/clean.go b/test/testdata/parity/boundaries/internal/domain/clean.go
new file mode 100644
index 0000000..550f2b8
--- /dev/null
+++ b/test/testdata/parity/boundaries/internal/domain/clean.go
@@ -0,0 +1,3 @@
+package domain
+
+type Value struct{ Name string }
diff --git a/test/testdata/parity/boundaries/internal/domain/model.go b/test/testdata/parity/boundaries/internal/domain/model.go
new file mode 100644
index 0000000..909861b
--- /dev/null
+++ b/test/testdata/parity/boundaries/internal/domain/model.go
@@ -0,0 +1,6 @@
+package domain
+
+// Violates the boundary: domain imports db.
+import _ "example.com/fixture/internal/db"
+
+type Entity struct{ ID string }
diff --git a/test/testdata/parity/disallowed-subtree/.structlint.yaml b/test/testdata/parity/disallowed-subtree/.structlint.yaml
new file mode 100644
index 0000000..f4d38d2
--- /dev/null
+++ b/test/testdata/parity/disallowed-subtree/.structlint.yaml
@@ -0,0 +1,13 @@
+dir_structure:
+  allowedPaths:
+    - "."
+    - "src/**"
+  disallowedPaths:
+    - "tmp/**"
+file_naming_pattern:
+  allowed:
+    - "*.go"
+    - "*.md"
+    - "*.yaml"
+ignore:
+  - ".git"
diff --git a/test/testdata/parity/disallowed-subtree/README.md b/test/testdata/parity/disallowed-subtree/README.md
new file mode 100644
index 0000000..4633334
--- /dev/null
+++ b/test/testdata/parity/disallowed-subtree/README.md
@@ -0,0 +1 @@
+# disallowed-subtree
diff --git a/test/testdata/parity/disallowed-subtree/src/main.go b/test/testdata/parity/disallowed-subtree/src/main.go
new file mode 100644
index 0000000..06ab7d0
--- /dev/null
+++ b/test/testdata/parity/disallowed-subtree/src/main.go
@@ -0,0 +1 @@
+package main
diff --git a/test/testdata/parity/disallowed-subtree/tmp/leftover.go b/test/testdata/parity/disallowed-subtree/tmp/leftover.go
new file mode 100644
index 0000000..14aed26
--- /dev/null
+++ b/test/testdata/parity/disallowed-subtree/tmp/leftover.go
@@ -0,0 +1 @@
+package tmp
diff --git a/test/testdata/parity/disallowed-subtree/tmp/nested/deeper.go b/test/testdata/parity/disallowed-subtree/tmp/nested/deeper.go
new file mode 100644
index 0000000..bdb515c
--- /dev/null
+++ b/test/testdata/parity/disallowed-subtree/tmp/nested/deeper.go
@@ -0,0 +1 @@
+package nested
diff --git a/test/testdata/parity/goldens/boundaries.exit b/test/testdata/parity/goldens/boundaries.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/test/testdata/parity/goldens/boundaries.exit
@@ -0,0 +1 @@
+1
diff --git a/test/testdata/parity/goldens/boundaries.json b/test/testdata/parity/goldens/boundaries.json
new file mode 100644
index 0000000..34d241b
--- /dev/null
+++ b/test/testdata/parity/goldens/boundaries.json
@@ -0,0 +1,33 @@
+✗ Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db
+{
+  "successes": 12,
+  "failures": 1,
+  "total_violations": 1,
+  "errors": [
+    "Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db"
+  ],
+  "violations": [
+    {
+      "code": "boundary_violation",
+      "severity": "error",
+      "path": "internal/domain/model.go",
+      "rule": "domain-no-infra",
+      "message": "Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db"
+    }
+  ],
+  "summary": {
+    "total_successes": 12,
+    "total_failures": 1,
+    "violations": [
+      {
+        "type": "boundary_violation",
+        "count": 1,
+        "examples": [
+          "Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db"
+        ],
+        "description": "Files importing paths forbidden by boundary rules"
+      }
+    ]
+  }
+}
+validation failed with 1 errors
diff --git a/test/testdata/parity/goldens/boundaries.text b/test/testdata/parity/goldens/boundaries.text
new file mode 100644
index 0000000..4a20228
--- /dev/null
+++ b/test/testdata/parity/goldens/boundaries.text
@@ -0,0 +1,15 @@
+✗ Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db
+
+--- Validation Summary ---
+✓ 12 files/directories passed validation
+✗ 1 violations found
+
+--- Validation Summary ---
+✓ 12 checks passed
+✗ 1 checks failed
+
+--- Violation Summary ---
+
+Files importing paths forbidden by boundary rules (1 violations):
+  - Boundary violation: internal/domain/model.go imports example.com/fixture/internal/db
+validation failed with 1 errors
diff --git a/test/testdata/parity/goldens/disallowed-subtree.exit b/test/testdata/parity/goldens/disallowed-subtree.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/test/testdata/parity/goldens/disallowed-subtree.exit
@@ -0,0 +1 @@
+1
diff --git a/test/testdata/parity/goldens/disallowed-subtree.json b/test/testdata/parity/goldens/disallowed-subtree.json
new file mode 100644
index 0000000..6c67a67
--- /dev/null
+++ b/test/testdata/parity/goldens/disallowed-subtree.json
@@ -0,0 +1,33 @@
+✗ Disallowed directory found: tmp
+{
+  "successes": 7,
+  "failures": 1,
+  "total_violations": 1,
+  "errors": [
+    "Disallowed directory found: tmp"
+  ],
+  "violations": [
+    {
+      "code": "disallowed_directory",
+      "severity": "error",
+      "path": "tmp",
+      "rule": "tmp/**",
+      "message": "Disallowed directory found: tmp"
+    }
+  ],
+  "summary": {
+    "total_successes": 7,
+    "total_failures": 1,
+    "violations": [
+      {
+        "type": "disallowed_directory",
+        "count": 1,
+        "examples": [
+          "Disallowed directory found: tmp"
+        ],
+        "description": "Directories that are explicitly disallowed"
+      }
+    ]
+  }
+}
+validation failed with 1 errors
diff --git a/test/testdata/parity/goldens/disallowed-subtree.text b/test/testdata/parity/goldens/disallowed-subtree.text
new file mode 100644
index 0000000..045ddff
--- /dev/null
+++ b/test/testdata/parity/goldens/disallowed-subtree.text
@@ -0,0 +1,15 @@
+✗ Disallowed directory found: tmp
+
+--- Validation Summary ---
+✓ 7 files/directories passed validation
+✗ 1 violations found
+
+--- Validation Summary ---
+✓ 7 checks passed
+✗ 1 checks failed
+
+--- Violation Summary ---
+
+Directories that are explicitly disallowed (1 violations):
+  - Disallowed directory found: tmp
+validation failed with 1 errors
diff --git a/test/testdata/parity/goldens/required-groups.exit b/test/testdata/parity/goldens/required-groups.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/test/testdata/parity/goldens/required-groups.exit
@@ -0,0 +1 @@
+1
diff --git a/test/testdata/parity/goldens/required-groups.json b/test/testdata/parity/goldens/required-groups.json
new file mode 100644
index 0000000..5d86da1
--- /dev/null
+++ b/test/testdata/parity/goldens/required-groups.json
@@ -0,0 +1,50 @@
+✗ Directory cmd/broken missing required file: main.go
+✗ Required group missing one of: Makefile, Taskfile.yml
+{
+  "successes": 9,
+  "failures": 2,
+  "total_violations": 2,
+  "errors": [
+    "Directory cmd/broken missing required file: main.go",
+    "Required group missing one of: Makefile, Taskfile.yml"
+  ],
+  "violations": [
+    {
+      "code": "missing_required_group",
+      "severity": "error",
+      "path": "build-entrypoint",
+      "rule": "build-entrypoint",
+      "message": "Required group missing one of: Makefile, Taskfile.yml"
+    },
+    {
+      "code": "missing_group_file",
+      "severity": "error",
+      "path": "cmd/broken/main.go",
+      "rule": "commands-have-main",
+      "message": "Directory cmd/broken missing required file: main.go"
+    }
+  ],
+  "summary": {
+    "total_successes": 9,
+    "total_failures": 2,
+    "violations": [
+      {
+        "type": "missing_group_file",
+        "count": 1,
+        "examples": [
+          "Directory cmd/broken missing required file: main.go"
+        ],
+        "description": "Directories missing files required by their group"
+      },
+      {
+        "type": "missing_required_group",
+        "count": 1,
+        "examples": [
+          "Required group missing one of: Makefile, Taskfile.yml"
+        ],
+        "description": "Required groups with no matching file"
+      }
+    ]
+  }
+}
+validation failed with 2 errors
diff --git a/test/testdata/parity/goldens/required-groups.text b/test/testdata/parity/goldens/required-groups.text
new file mode 100644
index 0000000..c13631a
--- /dev/null
+++ b/test/testdata/parity/goldens/required-groups.text
@@ -0,0 +1,19 @@
+✗ Directory cmd/broken missing required file: main.go
+✗ Required group missing one of: Makefile, Taskfile.yml
+
+--- Validation Summary ---
+✓ 9 files/directories passed validation
+✗ 2 violations found
+
+--- Validation Summary ---
+✓ 9 checks passed
+✗ 2 checks failed
+
+--- Violation Summary ---
+
+Directories missing files required by their group (1 violations):
+  - Directory cmd/broken missing required file: main.go
+
+Required groups with no matching file (1 violations):
+  - Required group missing one of: Makefile, Taskfile.yml
+validation failed with 2 errors
diff --git a/test/testdata/parity/required-groups/.structlint.yaml b/test/testdata/parity/required-groups/.structlint.yaml
new file mode 100644
index 0000000..69feaee
--- /dev/null
+++ b/test/testdata/parity/required-groups/.structlint.yaml
@@ -0,0 +1,20 @@
+dir_structure:
+  allowedPaths:
+    - "."
+    - "cmd/**"
+file_naming_pattern:
+  allowed:
+    - "*.go"
+    - "*.md"
+    - "*.yaml"
+requiredGroups:
+  - id: commands-have-main
+    eachDirMatching: "cmd/*"
+    mustContain:
+      - "main.go"
+  - id: build-entrypoint
+    oneOf:
+      - "Makefile"
+      - "Taskfile.yml"
+ignore:
+  - ".git"
diff --git a/test/testdata/parity/required-groups/README.md b/test/testdata/parity/required-groups/README.md
new file mode 100644
index 0000000..f4ea5f1
--- /dev/null
+++ b/test/testdata/parity/required-groups/README.md
@@ -0,0 +1 @@
+# required-groups
diff --git a/test/testdata/parity/required-groups/cmd/broken/helper.go b/test/testdata/parity/required-groups/cmd/broken/helper.go
new file mode 100644
index 0000000..904a86b
--- /dev/null
+++ b/test/testdata/parity/required-groups/cmd/broken/helper.go
@@ -0,0 +1,3 @@
+package main
+
+func Helper() {}
diff --git a/test/testdata/parity/required-groups/cmd/complete/main.go b/test/testdata/parity/required-groups/cmd/complete/main.go
new file mode 100644
index 0000000..38dd16d
--- /dev/null
+++ b/test/testdata/parity/required-groups/cmd/complete/main.go
@@ -0,0 +1,3 @@
+package main
+
+func main() {}
diff --git a/test/version_pragma_test.go b/test/version_pragma_test.go
new file mode 100644
index 0000000..64b03bb
--- /dev/null
+++ b/test/version_pragma_test.go
@@ -0,0 +1,69 @@
+package test
+
+import (
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// buildBinaryWithVersion builds a fresh structlint binary with a specific
+// build.Version injected via ldflags. Used to prove the version pragma
+// path fires end-to-end from a real CLI invocation.
+func buildBinaryWithVersion(t *testing.T, version string) string {
+	t.Helper()
+	dir := t.TempDir()
+	out := filepath.Join(dir, "structlint-pinned")
+	ldflags := "-X github.com/AxeForging/structlint/internal/build.Version=" + version
+	cmd := exec.Command("go", "build", "-o", out, "-ldflags", ldflags, "./cmd/structlint")
+	cmd.Dir = repoRoot(t)
+	if raw, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("build pinned binary: %v\n%s", err, string(raw))
+	}
+	return out
+}
+
+func TestVersionPragma_OldBinaryOnNewConfigFailsHelpfully(t *testing.T) {
+	bin := buildBinaryWithVersion(t, "v0.5.0")
+	dir := t.TempDir()
+	writeTestFile(t, dir, ".structlint.yaml", `# requires structlint >= v0.6.0
+dir_structure:
+  allowedPaths: ["."]
+file_naming_pattern:
+  allowed: ["*.md", "*.yaml"]
+ignore: [".git"]
+`)
+	writeTestFile(t, dir, "README.md", "# t\n")
+
+	out, err := runBinaryInDir(t, bin, dir, "validate", "--silent")
+	if err == nil {
+		t.Fatalf("expected failure: v0.5.0 binary should reject a >= v0.6.0 pragma, out:\n%s", out)
+	}
+	if !strings.Contains(out, "requires structlint >= v0.6.0") {
+		t.Errorf("error should quote the required version, got:\n%s", out)
+	}
+	if !strings.Contains(out, "running version is v0.5.0") {
+		t.Errorf("error should quote the running version, got:\n%s", out)
+	}
+	if !strings.Contains(out, "go install") {
+		t.Errorf("error should suggest an upgrade path, got:\n%s", out)
+	}
+}
+
+func TestVersionPragma_MatchingBinaryValidatesCleanly(t *testing.T) {
+	bin := buildBinaryWithVersion(t, "v0.6.5")
+	dir := t.TempDir()
+	writeTestFile(t, dir, ".structlint.yaml", `# requires structlint >= v0.6.0
+dir_structure:
+  allowedPaths: ["."]
+file_naming_pattern:
+  allowed: ["*.md", "*.yaml"]
+ignore: [".git"]
+`)
+	writeTestFile(t, dir, "README.md", "# t\n")
+
+	out, err := runBinaryInDir(t, bin, dir, "validate", "--silent")
+	if err != nil {
+		t.Fatalf("expected success: v0.6.5 satisfies >= v0.6.0, err=%v out:\n%s", err, out)
+	}
+}