Upgrade React and react-tooltip

[jleo3]

Summary

• upgrade React and React DOM to 19.2.7, react-tooltip to 6.0.8, and prop-types to 15.8.1
• align Testing Library with the React 19-compatible 16.3.2 release required by prerequisite issue Upgrade Jest and Testing Library #194
• add tooltip interaction coverage while preserving warning content and highlight placement
• make Chrome E2E manifest setup deterministic and worktree-safe
• apply the repository's current Prettier formatting to files that blocked the quality gate

Why

Issue #195 upgrades the extension UI dependencies without intentionally changing warning, options, content-editable, public API, or manifest behavior. The merged prerequisite still used Testing Library 14.3.1, whose peer range only supports React 18, so the dependency graph also needed the 16.3.2 version specified by #194.

The E2E suite additionally exposed an asynchronous manifest rewrite and a repository-name-specific file match. Awaiting setup/teardown and using a worktree-safe test-page match makes the generated Chrome extension smoke test reliable.

Validation

• npm test -- --runInBand — 254 tests passed across 7 suites
• npm run lint:check
• npm run format:check
• npm run build
• npm run e2e — 4 Chrome E2E/performance tests passed
• dependency tree validated with npm ls

Firefox smoke testing is not applicable to the unchanged Chrome MV3 manifest: Firefox rejects its background.service_worker field and requires a Gecko extension ID.

Closes #195