refactor(annotation): use #src subpath imports instead of parent-relative paths

[contextbotai]

What & why

The repo's AGENTS.md mandates subpath imports for intra-package references:

Subpath imports for intra-package refs: every package declares "imports": { "#src/*": "./src/*" } in its package.json. Code writes import { x } from '#src/context.ts'; for cross-directory imports. Same-directory siblings (e.g. plan.test.ts → ./plan.ts) may stay relative.

Every workspace package that has cross-directory code already declares and uses #src/* (9 of them: cli, context, harness, instrumentation, server, shared, skills, storage, ui). The @contextbridge/annotation package was the sole outlier — it never declared the imports map and reached across directories with parent-relative paths (../, ../../) instead of #src/*.

This was the single most egregious, clearly-defined, and safely-fixable violation class:

• Frequency: 23 offending import specifiers across 8 files.
• Severity: direct, unambiguous contradiction of a written convention that the rest of the monorepo already follows uniformly.
• Fixability: pure import-path rewrite; zero runtime-behavior change.

Changes

• Added "imports": { "#src/*": "./src/*" } to packages/annotation/package.json (matching the other packages).
• Rewrote all 23 parent-relative cross-directory imports to #src/* equivalents across:
  • src/demo/DemoStage.tsx
  • src/element/ElementAdapter.ts
  • src/element/useElementTargets.ts
  • src/element/mermaid/mermaidAdapter.ts
  • src/element/mermaid/mermaidAdapter.test.ts
  • src/element/mermaid/MermaidBlock.tsx
  • src/testHelpers/index.tsx
  • src/testHelpers/appContextDecorator.tsx
  • src/testHelpers/createFakeAppContext.ts
  • src/testHelpers/renderAnnotationHook.tsx
• Left same-directory sibling imports (./x) untouched, exactly as the convention permits.

Verification

• bun run format:check — clean
• bun run lint — clean (--max-warnings 0)
• bun run --cwd packages/annotation typecheck — clean
• packages/annotation vitest browser suite (Playwright/Chromium) — 151 tests / 12 files passing, confirming #src/* resolves in vitest browser mode.
• vite build (the production single-file bundle) — succeeds, confirming #src/* resolves through the vite bundler with no extra alias config.

Notes for reviewer / future runs

Other convention-violation classes I noticed but intentionally left for follow-up runs (one class per run):

• ?? fallbacks vs. destructured defaults — many ?? uses exist but most are legitimate (non-options-bag) usages; needs case-by-case review to avoid behavior changes.
• Hand-rolled createDeferred in packages/instrumentation/src/node/harnessDiscovery.test.ts should use the shared createDeferred from @contextbridge/shared/testHelpers per the testing-patterns rule.
• packages/cli/src/environment.ts uses .min(1) on a numeric PortSchema — the .nonempty() convention is specifically for string schemas, so this is likely NOT a violation.