feat(cases): add local case workspace foundation

[luandro]

Closes #268
Refs #145

Summary

• Adds the Dexie v13 local Case, metadata-only activity, and independent per-agency report-state foundation.
• Implements offline-first Case CRUD, lifecycle transitions, strict project isolation, and the exact Brazil v1 ten-category taxonomy.
• Requests persistent browser storage and surfaces eviction/quota-risk states without blocking local Case work.
• Adds local TanStack Query hooks and /cases, /cases/new, and /cases/$caseId routes.
• Keeps Case activity metadata-only and Case/provider operations local-only with privacy/no-network regression coverage.
• Ships localized en/pt/es Case UI plus Storybook coverage and desktop/mobile E2E.

Testing

• npm run validate — PASS on the exact committed tree.
  • 237 unit test files passed.
  • 2916 tests passed, 1 skipped.
  • Coverage: 89.27% statements / 83.87% branches / 89.44% functions / 91.01% lines.
• Focused feat(cases): Cases foundation + local model/lifecycle/navigation #268 unit/component suite: 223/223 passed.
• Strict TypeScript: PASS.
• Full ESLint: PASS.
• Full Prettier: PASS.
• React Doctor changed-file scan: 0 findings.
• Storybook static build: PASS.
• Chromium Cases E2E: 2/2 PASS at 1440x900 desktop and 375x812 mobile.
• npm run check:i18n: PASS.

Review

• Adversarial pre-commit review completed with: No actionable findings.

Out of scope

• feat(cases): Evidence selection + disclosure foundation #269 evidence/disclosure
• feat(reports): Project report branding #270 branding
• feat(reports): Brazil template registry + Case Facts contract #271 templates / Case Facts
• feat(reports): Cloudflare AI generation + editor #272 Cloudflare AI
• feat(reports): Groq Whisper voice editing with ZDR guard #273 Groq voice / ZDR
• feat(reports): BYOM providers + model profiles #274 BYOM
• feat(cases): Remote Case/report sync + authorization #275 remote D1/R2 sync
• feat(reports): Finalization + PDF/evidence bundle + sharing #276 finalization / PDF / share
• test(cases/reports): Cross-feature privacy/offline hardening + QA #277 whole-stack hardening

Do not merge as part of this task; this PR is for human QA/review.

[github-actions]

React Doctor found no new issues. 🎉

_{Reviewed by React Doctor for commit 6e9a255.}

[github-actions]

Preview deployment ready: https://issue-268-cases-foundation.comapeo-cloud-app.pages.dev

Commit: c8e2cb4