test(ci): select component suites by affected dependencies

[opencode-agent]

Summary

Schedule the app and session-ui component browser suites independently in the test workflow, using Turbo's affected workspace graph plus explicit shared-harness exceptions.

This is a stacked follow-up to #45142, targeting app-component-tests at 08e60630fe. The predecessor is still open and owns the component suite infrastructure. This PR adds only the CI filtering and concurrent-server isolation; it does not modify or merge the predecessor. Retarget/rebase this follow-up onto v2 after that infrastructure lands.

Selection

• App implementation, app stories, or app component specs: app components and full-app E2E; skip session-ui components.
• Session-ui changes: session-ui components plus dependent app suites. Shared UI, client, util, and other workspace dependencies propagate through Turbo.
• Shared Storybook config, mocks, mount fixtures, and stories: both component suites. A harness-only change does not enable full-app E2E.
• The preview imports app CSS and LanguageProvider outside the workspace graph. Explicit shared exceptions cover app CSS, public assets, localization, and its persistence/platform/server-registry/server-scope/path-key runtime dependency chain. An always-run import-closure test checks these exceptions against the real preview imports, including dynamic locale imports, rather than assuming localization is self-contained. The platform branch is conservatively covered even where Storybook mocks it.
• Lockfiles, manifests, TypeScript/Turbo configuration, root tooling, unknown non-documentation paths, manual dispatch, and failed Git/Turbo comparisons select all browser suites. Unrelated documentation skips them.

PR comparisons use the tested merge ref's first parent; pushes use the event's previous SHA. Both use a merge base. Deleted files and both paths of a rename are included. Missing/zero refs fail safe.

Each component package gets its own Linux job and artifact upload. Existing unit jobs, Linux/Windows E2E check names, and the existing E2E exclusion for refs named v2 are unchanged. That exclusion still applies to manual dispatch. No performance or unrelated browser suites are enabled.

Local concurrent Turbo tasks use separate ports (session-ui 6006, app 6007) and separate Vite optimization caches. Running both suites exposed a shared-cache race despite separate ports; isolating both resources resolves the module-fetch failures.

Validation

• bun test --root . browser-suites.test.ts from script/github: 39 passing tests using real synthetic Git commits and Turbo 2.10.2 with the repository's actual workspace manifests.
• Matrix includes app-only changes, session-ui, UI/client/util dependents, Storybook inputs, CSS/i18n/transitive shared imports, lockfiles/config, unknown paths, unrelated docs, deletion/rename, diverged branches, PR merge refs, push refs, manual dispatch, missing refs, and Turbo failure.
• Concurrent bun turbo test:components --filter=@opencode-ai/app --filter=@opencode-ai/session-ui: final run passed all 45 tests without retries (44 session-ui, 1 app). A prior cold-cache run passed with two session lifecycle retries; assertions and retry settings are unchanged.
• bun typecheck in app and session-ui passed.
• Turbo dry-run confirms exactly the two uncached component tasks.
• Selector CLI checked for the real stacked diff and manual dispatch.
• Actionlint 1.7.11 passed with the existing Blacksmith runner labels configured; Prettier and git diff --check passed.
• Full-app E2E journeys were not rerun locally; their commands and ref exclusion are unchanged.

Requested by: @Brendonovich (Brendan via Slack)