chore: add UI styles and update documentation

- Add cart drawer and product gallery thumbnail CSS
- Remove redundant type="text/javascript" attribute
- Update image optimization plan to reflect completion

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/plans/image-optimization.md

@@ -7,21 +7,21 @@
 
 ## Progress Tracker
 
-**Current Phase:** Not started
+**Current Phase:** Complete
 **Last Updated:** 2026-01-21
 
 | Phase | Status | Commit |
 |-------|--------|--------|
-| 1. Oban dependency + config | ⬜ Pending | - |
-| 2. Migration + Schema | ⬜ Pending | - |
-| 3. Optimizer module | ⬜ Pending | - |
-| 4. Oban worker | ⬜ Pending | - |
-| 5. Media module integration | ⬜ Pending | - |
-| 6. VariantCache GenServer | ⬜ Pending | - |
-| 7. Responsive image component | ⬜ Pending | - |
-| 8. ImageController disk serving | ⬜ Pending | - |
-| 9. Mix task for mockups | ⬜ Pending | - |
-| 10. Final integration + Lighthouse | ⬜ Pending | - |
+| 1. Oban dependency + config | ✅ Complete | dbadd2a |
+| 2. Migration + Schema | ✅ Complete | cefec1a |
+| 3. Optimizer module | ✅ Complete | 2b5b749 |
+| 4. Oban worker | ✅ Complete | 2b5b749 |
+| 5. Media module integration | ✅ Complete | (pending commit) |
+| 6. VariantCache GenServer | ✅ Complete | (pending commit) |
+| 7. Responsive image component | ✅ Complete | (pending commit) |
+| 8. ImageController disk serving | ✅ Complete | (pending commit) |
+| 9. Mix task for mockups | ✅ Complete | (pending commit) |
+| 10. Final integration + Lighthouse | ✅ Complete | (pending commit) |
 
 **Legend:** ⬜ Pending | 🔄 In Progress | ✅ Complete | ❌ Blocked