docs: reconcile documentation with reality (P3)

Make the project's documentation match the code and remove the sprawl. The docs
claimed Phase 2.8 (drug interactions) was 'planning/0%' and the backend '~91%
complete' — both wrong: 2.8 is implemented and live, plus the P0/P1 security
and test work is done. Five root CI/CD docs described a 'docker-build' CI job
that was removed; ~18 backend/ status snapshots and ~24 docs/implementation
duplicates cluttered the tree.

Deletions (85 files):
- Root: 4 stale CI/CD reports (CI-CD-{COMPLETION-REPORT,IMPLEMENTATION-SUMMARY,
  STATUS-REPORT,FINAL-STATUS}.md) — all describe the removed docker-build job.
- backend/: 18 phase/build/fix snapshots and code-dump .txt files.
- docs/: the 3 one-time reorg reports; ~17 docs/implementation duplicates and
  process artifacts; 4 stale docs/development CI docs + git snapshots;
  redundant deployment/testing files.
- thoughts/: STATUS.md (said Phase 2.4 in-progress), superseded phase notes and
  duplicative research inputs. tmp/ (928KB of CI debug logs, gitignored).

Moves (18 files):
- 9 genuine decision records -> docs/adr/ (Architecture Decision Records),
  date-prefixes stripped, with an index README.
- 8 historical-but-valuable phase plans/specs + the old CI-CD-FINAL-SOLUTION ->
  docs/archive/ (now-populated, with a README explaining it's superseded
  material). thoughts/ tree removed.

Rewrites (13 files) to match reality:
- Drop the fake '% complete' figures everywhere in favor of Implemented /
  In-Progress / Planned with concrete endpoint/feature lists.
- Phase 2.8 -> Implemented; add /api/interactions/* and /api/auth/{refresh,
  logout} to the endpoint lists; fix 'Rust 1.93' -> edition 2021.
- Add a Security section (token_version validation, hashed refresh-token
  persistence, fail-fast config, real-IP audit) and correct the test-coverage
  and deployment claims to reality.
- New canonical docs/development/CI-CD.md (4 jobs: format/clippy/build/test,
  mongo service, no docker-build + why).
- README, docs/README, product/{STATUS,ROADMAP,PROGRESS,README,introduction},
  implementation/README, development/README, testing/README, AI_AGENT_GUIDE,
  .cursorrules, .gooserules all updated.

Verified: greps for 'Phase 2.8 (Planning)', 'PLANNING (0%)', 'Rust 1.93',
'91%/10%/85% complete', and 'docker-build' return nothing outside docs/archive;
all internal doc links resolve; backend/src untouched (cargo build clean).

docs/adr/state-management-decision.md

@@ -0,0 +1,106 @@
+# State Management Decision Summary
+
+**Date**: 2026-02-14
+**Decision**: **Redux Toolkit 2.x**
+
+---
+
+## Scorecard
+
+| Criterion | Redux Toolkit | Zustand | Jotai | Weight |
+|-----------|---------------|----------|--------|--------|
+| Code Sharing | 10 | 10 | 10 | Critical |
+| Bundle Size | 7 | 10 | 10 | Critical |
+| TypeScript | 10 | 10 | 10 | Critical |
+| Complex State | 10 | 7 | 5 | Critical |
+| Offline Sync | 10 | 7 | 5 | Critical |
+| **Weighted Score** | **9.2** | 8.6 | 7.6 | - |
+
+---
+
+## Decision: Redux Toolkit 2.x
+
+**Score**: 9.2/10
+
+### Key Advantages
+
+1. **Best for Complex State**
+   - Family structure, multi-person profiles, permissions
+   - Built-in normalization (createEntityAdapter)
+   - Predictable state updates
+   - Time-travel debugging
+
+2. **Best for Offline Sync**
+   - RTK Query for server state management
+   - Optimistic updates
+   - Background sync support
+   - Battle-tested offline patterns
+
+3. **Best Ecosystem**
+   - Largest ecosystem
+   - Most resources, tutorials, examples
+   - Most production deployments
+   - Easiest to hire developers
+
+4. **Best Developer Experience**
+   - Time-travel debugging
+   - Predictable state updates
+   - Easy to debug
+
+### Trade-offs
+
+- More boilerplate: More code, but clearer structure
+- Steeper learning curve: More concepts, but better patterns
+- Larger bundle: 60KB vs 3KB (negligible impact on 50-100MB app)
+
+---
+
+## Technology Stack
+
+### Shared (Monorepo)
+- **State Management**: Redux Toolkit 2.x
+- **Data Fetching**: RTK Query 2.x
+- **Async Thunks**: createAsyncThunk
+- **Persistence**: Redux Persist 6.x
+- **Selectors**: Reselect 5.x
+- **DevTools**: Redux DevTools
+
+---
+
+## Alternative Considered: Zustand
+
+**Score**: 8.6/10
+
+**Why Redux Toolkit wins**:
+- Better for complex state (family structure)
+- Better for offline sync (RTK Query)
+- Larger ecosystem (more resources)
+
+**When to use Zustand instead**:
+- If team has no Redux experience
+- If state is simpler (no family structure)
+- If development speed is more important
+
+---
+
+## Next Steps
+
+1. Implement Redux Toolkit POC
+2. Create family structure state slice
+3. Implement RTK Query for server state
+4. Test offline synchronization
+5. Test encrypted data caching
+6. Make final decision
+
+---
+
+## Implementation Timeline
+
+- Setup Redux Toolkit: 1 day
+- Create state slices: 2-3 days
+- Implement RTK Query: 2-3 days
+- Implement offline sync: 3-5 days
+- Test encrypted caching: 2-3 days
+- Evaluate DX: 1-2 days
+
+**Total**: 11-17 days (2-3 weeks)