Release v0.6.0

[JRS1986]

Summary

Cuts the v0.6.0 release. Three small file changes following the past-release pattern:

• CHANGELOG.md — promote the [Unreleased] block to ## [0.6.0] — 2026-05-27.
• pyproject.toml — version bump 0.5.1 → 0.6.0.
• uv.lock — refresh to record the new package version.

What's in 0.6.0

Cumulative changes since 0.5.1 (see CHANGELOG for the full breakdown):

Added

• Multi-tool projects: --tool accepts a list across setup run, tools adapt, setup tool, and pilot
• coding-scaffold tour — five-screen walkthrough
• --persona flag on doctor and pilot
• Stability markers in --help ([stable] / [preview] / [experimental])
• Per-subcommand --help descriptions and examples
• Doctor rationale lines (per-artifact "why this matters")
• setup update --force + min_supported_scaffold_version field
• setup update prints a .new reconciliation recipe inline

Fixed

• Template renderer no longer leaks ${undefined} into user files

Changed (breaking)

• routing.json, project.json, and pilot JSON output now carry tools (a list) only — singular tool key gone (back-fill in place for one release)
• Unified error message style (fail_with three-line shape)

Deprecated

• --tool both → removal scheduled for 0.7.0

Documentation

• New wiki pages: Glossary, Stability, Upgrading, Errors-and-Recovery

Tests

• 351 → 635 tests passing

Test plan

• uv run pytest -q — 635 tests pass.
• uv run ruff check src/ tests/ — clean.
• No code changes — release-only commit.