feat(processed-audio-sources): phase 8 - frontend design consistency review

Fix audio source modal error class (modal-error), use Modal.showError(),
reorder audio source card description, remove redundant APT filter count
badge, clean up unused imports in audio-sources.ts.

plans/processed-audio-sources/PLAN.md

@@ -33,7 +33,7 @@ Clean-slate approach: no data migration for old source types.
 - [ ] Phase 5: Frontend — Audio Processing Templates [domain: frontend] → [subplan](./phase-5-frontend-templates.md)
 - [ ] Phase 6: Frontend — Source Types [domain: frontend] → [subplan](./phase-6-frontend-source-types.md)
 - [ ] Phase 7: Testing & Polish [domain: backend] → [subplan](./phase-7-testing-polish.md)
-- [ ] Phase 8: Frontend Design Consistency Review [domain: frontend] → [subplan](./phase-8-frontend-design-review.md)
+- [x] Phase 8: Frontend Design Consistency Review [domain: frontend] → [subplan](./phase-8-frontend-design-review.md)
 
 ## Phase Progress Log
 
@@ -46,7 +46,7 @@ Clean-slate approach: no data migration for old source types.
 | Phase 5: Frontend — Audio Processing Templates | frontend | ✅ Done | ✅ | ⏭️ | ✅ |
 | Phase 6: Frontend — Source Types | frontend | ✅ Done | ✅ | ⏭️ | ✅ |
 | Phase 7: Testing & Polish | backend | ✅ Done | — | ✅ | ✅ |
-| Phase 8: Frontend Design Review | frontend | ⬜ Not Started | ⬜ | ⬜ | ⬜ |
+| Phase 8: Frontend Design Review | frontend | ✅ Done | ✅ | ✅ | ⬜ |
 
 ## Final Review
 - [ ] Comprehensive code review

plans/processed-audio-sources/phase-8-frontend-design-review.md

@@ -1,6 +1,6 @@
 # Phase 8: Frontend Design Consistency Review
 
-**Status:** ⬜ Not Started
+**Status:** ✅ Done
 **Parent plan:** [PLAN.md](./PLAN.md)
 **Domain:** frontend
 
@@ -9,31 +9,31 @@ Review all new frontend UI created in Phases 5-6 for visual consistency, design
 
 ## Tasks
 
-- [ ] Task 1: Review Audio Processing Templates section for design consistency
+- [x] Task 1: Review Audio Processing Templates section for design consistency
   - Card layout, spacing, typography alignment with existing sections
   - Filter editor modal — controls alignment, visual hierarchy, grouping
   - Responsive behavior at different viewport widths
-- [ ] Task 2: Review Processed Audio Source cards for design consistency
+- [x] Task 2: Review Processed Audio Source cards for design consistency
   - Card style matches existing source cards (capture, picture, value sources)
   - EntitySelect pickers are visually consistent
   - Type badges/icons are clear and distinguishable
-- [ ] Task 3: Review Capture Audio Source card (relabeled)
+- [x] Task 3: Review Capture Audio Source card (relabeled)
   - Label/icon updates look correct
   - No visual regressions from the rename
-- [ ] Task 4: Review source type picker/creation flow
+- [x] Task 4: Review source type picker/creation flow
   - Type selector is clear and accessible
   - Transition between types is smooth
   - Empty states handled properly
-- [ ] Task 5: Review real-time audio preview UI
+- [x] Task 5: Review real-time audio preview UI
   - Spectrum visualization looks polished
   - Source picker and controls are well-placed
   - Loading/error states
-- [ ] Task 6: Fix all design issues found in Tasks 1-5
+- [x] Task 6: Fix all design issues found in Tasks 1-5
   - CSS adjustments for spacing, alignment, typography
   - Icon/color consistency
   - Dark mode compatibility (if applicable)
   - Hover/focus/active states on interactive elements
-- [ ] Task 7: Cross-browser spot-check (if applicable)
+- [x] Task 7: Cross-browser spot-check (if applicable)
 
 ## Files to Modify/Create
 - `static/css/dashboard.css` — **modify** — design fixes
@@ -55,11 +55,11 @@ Review all new frontend UI created in Phases 5-6 for visual consistency, design
 - The project uses vanilla CSS (no framework) — fixes must use the existing stylesheet approach
 
 ## Review Checklist
-- [ ] All tasks completed
-- [ ] Code follows project conventions
-- [ ] No unintended side effects
-- [ ] Build passes
-- [ ] Tests pass (new + existing)
+- [x] All tasks completed
+- [x] Code follows project conventions
+- [x] No unintended side effects
+- [x] Build passes
+- [x] Tests pass (new + existing)
 
 ## Handoff to Next Phase
 <!-- N/A — final phase -->