docs(06-01): complete carousel navigation plan

Tasks completed: 1/1
- Install embla-carousel-react and create MobileCarousel component

SUMMARY: .planning/phases/06-carousel-navigation/06-01-SUMMARY.md

Author: pineapplestrikesback

.planning/STATE.md

@@ -5,24 +5,24 @@
 See: .planning/PROJECT.md (updated 2026-01-18)
 
 **Core value:** The body itself must carry the primary signal - users see training distribution at a glance without reading numbers.
-**Current focus:** Phase 5 - Muscle List (Complete)
+**Current focus:** Phase 6 - Carousel Navigation (In Progress)
 
 ## Current Position
 
-Phase: 5 of 9 (Muscle List)
-Plan: 2 of 2 in current phase
-Status: Phase complete
-Last activity: 2026-01-22 - Completed 05-02-PLAN.md
+Phase: 6 of 9 (Carousel Navigation)
+Plan: 1 of 2 in current phase
+Status: In progress
+Last activity: 2026-01-22 - Completed 06-01-PLAN.md
 
-Progress: [=======...] 67%
+Progress: [========..] 75%
 
 ## Performance Metrics
 
 **Velocity:**
 
-- Total plans completed: 8
-- Average duration: 2.9 min
-- Total execution time: 23 min
+- Total plans completed: 9
+- Average duration: 2.8 min
+- Total execution time: 25 min
 
 **By Phase:**
 
@@ -33,11 +33,12 @@ Progress: [=======...] 67%
 | 03-heatmap-core         | 2     | 7 min | 3.5 min  |
 | 04-front-back-toggle    | 1     | 2 min | 2 min    |
 | 05-muscle-list          | 2     | 3 min | 1.5 min  |
+| 06-carousel-navigation  | 1     | 2 min | 2 min    |
 
 **Recent Trend:**
 
-- Last 5 plans: 3 min, 4 min, 2 min, 1 min, 2 min
-- Trend: Stable (faster on smaller plans)
+- Last 5 plans: 4 min, 2 min, 1 min, 2 min, 2 min
+- Trend: Stable (consistently fast on focused plans)
 
 _Updated after each plan completion_
 
@@ -68,6 +69,10 @@ Recent decisions affecting current work:
 - Progress bar width clamped to 100% (data can exceed but bar fills at max)
 - Group totals replace muscle count badge in headers for actionable info
 - formatVolume shows whole numbers without decimals, fractions with one decimal
+- embla-carousel-react over custom touch handling for iOS Safari compatibility
+- loop: false for 2-slide carousels (loop breaks with only 2 slides in Embla)
+- touch-pan-y CSS class for vertical scroll compatibility on carousels
+- Elongated active dot (w-4) vs round inactive (w-2) for carousel indicators
 
 ### Patterns Established
 
@@ -92,17 +97,21 @@ Recent decisions affecting current work:
 - **LIST-DATA-02:** statsMap via useMemo for O(1) muscle lookup
 - **LIST-PROGRESS-01:** w-24 h-2 progress bar with rounded-full and dynamic backgroundColor
 - **LIST-SUMMARY-01:** Group headers show aggregate volume with getVolumeColor
+- **NAV-EMBLA-01:** useEmblaCarousel with loop: false for 2-slide carousels
+- **NAV-DOT-01:** Track selected index via emblaApi.on('select') event
+- **NAV-A11Y-01:** aria-label and aria-selected on dot indicators for accessibility
+- **NAV-SCROLL-01:** touch-pan-y class on flex container allows vertical scroll
 
 ### Pending Todos
 
 None.
 
 ### Blockers/Concerns
 
-None - Phase 05 complete, ready for Phase 06 (mobile layout integration).
+None - Phase 06 Plan 01 complete, carousel ready for integration.
 
 ## Session Continuity
 
-Last session: 2026-01-22T21:51:38Z
-Stopped at: Completed 05-02-PLAN.md (Phase 05 complete)
+Last session: 2026-01-22T22:19:38Z
+Stopped at: Completed 06-01-PLAN.md
 Resume file: None

.planning/phases/06-carousel-navigation/06-01-SUMMARY.md

@@ -0,0 +1,132 @@
+---
+phase: 06-carousel-navigation
+plan: 01
+subsystem: ui
+tags: [embla-carousel-react, react, tailwind, mobile, swipe-navigation, touch-gestures]
+
+# Dependency graph
+requires:
+  - phase: 05-muscle-list
+    provides: MobileHeatmap and MobileMuscleList components as carousel slides
+provides:
+  - MobileCarousel component with swipeable horizontal navigation
+  - Dot indicators tracking current slide position
+  - Instagram-style touch gesture UX with physics-based swipe
+affects: [06-02-integrate-carousel, mobile-dashboard]
+
+# Tech tracking
+tech-stack:
+  added: [embla-carousel-react v8.6.0]
+  patterns: [carousel-with-embla, touch-pan-y-for-vertical-scroll, dot-indicators-with-select-event]
+
+key-files:
+  created:
+    - src/ui/components/mobile/MobileCarousel.tsx
+  modified:
+    - package.json
+    - package-lock.json
+
+key-decisions:
+  - "Used embla-carousel-react over custom touch handling (iOS Safari quirks, physics-based swipe)"
+  - "Set loop: false for 2-slide carousel (loop breaks with only 2 slides - known Embla limitation)"
+  - "Added touch-pan-y CSS class for vertical scroll compatibility"
+  - "Elongated active dot (w-4) vs round inactive (w-2) for clear visual affordance"
+
+patterns-established:
+  - "NAV-EMBLA-01: useEmblaCarousel with loop: false for 2-slide carousels"
+  - "NAV-DOT-01: Track selected index via emblaApi.on('select') event"
+  - "NAV-A11Y-01: aria-label and aria-selected on dot indicators for accessibility"
+  - "NAV-SCROLL-01: touch-pan-y class on flex container allows vertical scroll"
+
+# Metrics
+duration: 2min
+completed: 2026-01-22
+---
+
+# Phase 06 Plan 01: Carousel Navigation Summary
+
+**Swipeable carousel with embla-carousel-react enables horizontal navigation between body heatmap and muscle list via touch gestures**
+
+## Performance
+
+- **Duration:** 2 min
+- **Started:** 2026-01-22T22:17:22Z
+- **Completed:** 2026-01-22T22:19:38Z
+- **Tasks:** 1
+- **Files modified:** 3
+
+## Accomplishments
+- Installed embla-carousel-react v8.6.0 (~7KB gzipped)
+- Created MobileCarousel component with Instagram-style swipe UX
+- Implemented dot indicators synchronized with slide changes via select event
+- Configured carousel for 2-slide navigation (loop: false to prevent known bug)
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Install embla-carousel-react and create MobileCarousel component** - `3b2e7b5` (feat)
+
+## Files Created/Modified
+- `src/ui/components/mobile/MobileCarousel.tsx` - Swipeable carousel container with dot navigation
+- `package.json` - Added embla-carousel-react dependency
+- `package-lock.json` - Locked dependency versions
+
+## Decisions Made
+
+**1. Library choice: embla-carousel-react over custom touch handling**
+- Rationale: Physics-based swipe (momentum, snap, velocity) is subtle and hard to perfect manually
+- iOS Safari has touch event quirks that library handles automatically
+- Bundle cost minimal (~7KB gzipped) vs 50-100 lines saved
+- Industry standard with 800K weekly downloads
+
+**2. Carousel configuration: loop: false**
+- Rationale: Known Embla bug - loop mode breaks with only 2 slides
+- Creates erratic behavior and stuck positions
+- Documented in RESEARCH.md and GitHub issues
+
+**3. Touch handling: touch-pan-y CSS class**
+- Rationale: Allows vertical scroll while enabling horizontal swipe
+- Prevents horizontal browser scroll conflict
+- Better than manual preventDefault logic
+
+**4. Dot indicator style: elongated active (w-4) vs round inactive (w-2)**
+- Rationale: Clear visual affordance for current position
+- Matches Instagram/mobile carousel UX patterns
+- Active dot uses amber-500 (brand accent color)
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 2 - Missing Critical] Added explicit return type to scrollTo callback**
+- **Found during:** Task 1 (ESLint check after component creation)
+- **Issue:** TypeScript ESLint requires explicit return types on exported functions and callbacks
+- **Fix:** Added `: void` return type to scrollTo callback and useEffect cleanup function
+- **Files modified:** src/ui/components/mobile/MobileCarousel.tsx
+- **Verification:** `npm run lint` passes with no warnings for MobileCarousel
+- **Committed in:** 3b2e7b5 (Task 1 commit - fixed before commit)
+
+---
+
+**Total deviations:** 1 auto-fixed (1 missing critical type annotation)
+**Impact on plan:** Auto-fix essential for code quality standards. No scope creep.
+
+## Issues Encountered
+None - plan executed smoothly with embla-carousel-react working as expected.
+
+## User Setup Required
+None - no external service configuration required.
+
+## Next Phase Readiness
+- MobileCarousel component ready for integration into mobile dashboard
+- Phase 06-02 can integrate carousel into Dashboard.tsx mobile view
+- Dot indicators provide clear navigation feedback
+- Swipe gesture UX matches Instagram-style mobile app patterns
+
+**Blockers:** None
+**Concerns:** None - carousel tested with build and lint, ready for visual verification in next phase
+
+---
+*Phase: 06-carousel-navigation*
+*Completed: 2026-01-22*