refactor(annotation): use #src/* subpath imports over ../ relative imports

[contextbotai]

What & why

The root AGENTS.md Imports convention states:

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 … may stay relative.

A repo-wide scan found this was the single most-violated convention class. All 26 cross-directory ../ / ../../ intra-package imports lived in @contextbridge/annotation — the one library package that also failed to declare the #src/* mapping. Every other package (cli, context, harness, instrumentation, server, shared, skills, storage, ui) already declares the mapping and uses #src/*.

This is the most egregious class by all three ranking axes: highest frequency (26 instances vs. 0–1 for other candidates), unambiguous contradiction of an explicit convention, and safe to fix with zero runtime behavior change.

Changes

• packages/annotation/package.json — added "imports": { "#src/*": "./src/*" } (placed after "type", matching sibling packages).
• Rewrote all 26 cross-directory imports across 11 files in packages/annotation/src/** from ../ / ../../ to #src/*. Same-directory ./ sibling imports were intentionally left relative, as the convention permits.

Files touched: demo/DemoStage.tsx, element/ElementAdapter.ts, element/mermaid/MermaidBlock.tsx, element/mermaid/mermaidAdapter.ts, element/mermaid/mermaidAdapter.test.ts, element/useElementTargets.ts, testHelpers/FakeThemeController.ts, testHelpers/appContextDecorator.tsx, testHelpers/createFakeAppContext.ts, testHelpers/index.tsx, testHelpers/renderAnnotationHook.tsx.

Verification

• bun run --cwd packages/annotation typecheck — passes (confirms #src/* resolves under tsc bundler resolution and Node package imports).
• bun run format:check — passes.
• bun run lint (--max-warnings 0) — passes.
• Annotation vitest browser suite — 13 files / 159 tests pass (installed the Playwright Chromium headless shell locally, which was missing from the sandbox, to run the browser-mode tests and confirm the new import paths resolve at runtime).

The only remaining ../../ references in the codebase are cross-package bundled-asset text imports (../../../annotation/dist/index.html, ../../../harnessIntegrations/.../SKILL.md) which intentionally reach into build outputs and are outside the intra-package subpath convention.

Other violation classes noted (not addressed, per one-class-per-run)

• Missing #src/* mapping in packages/review — the review package also lacks the imports field, but it's a WIP scaffold with no cross-directory imports yet, so there's nothing to convert.
• Hand-rolled createDeferred in packages/instrumentation/src/node/harnessDiscovery.test.ts (1 instance) — violates the testing-patterns rule "Use the shared deferred-promise helper; do not hand-roll it" (@contextbridge/shared/testHelpers).
• Hand-rolled createXxx() test fixtures with inline object literals (e.g. createHookDependencies, createFakeReviewDeps, createReportFixture, createFakeClient) instead of Fishery Factory.define<T>() factories — several instances across cli/context/instrumentation test files.