Implement Phase 10: e-ink polish and finalize project docs

- High-contrast theme with expanded color palette for e-ink readability
- Updated source trees in DESIGN.md
- Updated PROJECT_PLAN.md and PROGRESS.md — all phases complete
  (only on-device performance profiling remains)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

PROGRESS.md

@@ -102,9 +102,20 @@ See PROJECT_PLAN.md for the full step list.
 - [x] 9.2: Share via Intent.ACTION_SEND + FileProvider (configured in Phase 1)
 - [x] 9.3: PDF button in editor toolbar, exports current page
 
-## In Progress
+### Phase 10: Polish (2026-03-24)
 
-Phase 10: Polish
+- [x] 10.1: High-contrast e-ink theme — expanded color scheme with proper
+  container, variant, and outline colors for readability
+- [x] 10.2: Auto-save already in place since Phase 3 (strokes save on completion)
+- [x] 10.3: Empty states and delete confirmations already in place from Phase 2
+- [ ] 10.4: Performance profiling — requires on-device testing
+
+## Status
+
+All implementation phases complete. Remaining work:
+- On-device testing on Supernote Manta and Daylight DC-1
+- Performance profiling (stroke rendering, page load times)
+- Manual verification of PDF export fidelity
 
 ## Decisions & Deviations