Add color-coded backgrounds to DecisionCard

Per dashboard.md spec requirements:
- RED background and text for REST decisions
- YELLOW background and text for GENTLE/LIGHT/REDUCED decisions
- GREEN background and text for TRAIN decisions

Added 8 new tests for color-coded backgrounds (19 total).
Updated IMPLEMENTATION_PLAN.md to mark spec gap as complete.

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

IMPLEMENTATION_PLAN.md

@@ -4,7 +4,7 @@ This file is maintained by Ralph. Run `./ralph-sandbox.sh plan 3` to generate ta
 
 ## Current State Summary
 
-### Overall Status: 841 tests passing across 44 test files
+### Overall Status: 849 tests passing across 44 test files
 
 ### Library Implementation
 | File | Status | Gap Analysis |
@@ -113,7 +113,7 @@ This file is maintained by Ralph. Run `./ralph-sandbox.sh plan 3` to generate ta
 | `src/app/settings/page.test.tsx` | **EXISTS** - 34 tests (form rendering, validation, submission, accessibility, logout functionality) |
 | `src/app/api/auth/logout/route.test.ts` | **EXISTS** - 5 tests (cookie clearing, success response, error handling) |
 | `src/app/settings/garmin/page.test.tsx` | **EXISTS** - 27 tests (connection status, token management) |
-| `src/components/dashboard/decision-card.test.tsx` | **EXISTS** - 11 tests (rendering, status icons, styling) |
+| `src/components/dashboard/decision-card.test.tsx` | **EXISTS** - 19 tests (rendering, status icons, styling, color-coded backgrounds) |
 | `src/components/dashboard/data-panel.test.tsx` | **EXISTS** - 18 tests (biometrics display, null handling, styling) |
 | `src/components/dashboard/nutrition-panel.test.tsx` | **EXISTS** - 12 tests (seeds, carbs, keto guidance) |
 | `src/components/dashboard/override-toggles.test.tsx` | **EXISTS** - 18 tests (toggle states, callbacks, styling) |
@@ -702,18 +702,18 @@ Testing, error handling, and refinements.
 ### P3.11: Missing Component Tests ✅ COMPLETE
 - [x] Add unit tests for untested components
 - **Components Tested (5 total):**
-  - `src/components/dashboard/decision-card.tsx` - 11 tests for rendering decision status, icon, reason, styling
+  - `src/components/dashboard/decision-card.tsx` - 19 tests for rendering decision status, icon, reason, styling, color-coded backgrounds
   - `src/components/dashboard/data-panel.tsx` - 18 tests for biometrics display (BB, HRV, intensity), null handling, styling
   - `src/components/dashboard/nutrition-panel.tsx` - 12 tests for seeds, carbs, keto guidance display
   - `src/components/dashboard/override-toggles.tsx` - 18 tests for toggle states, callbacks, styling
   - `src/components/calendar/day-cell.tsx` - 23 tests for phase coloring, today highlighting, click handling
 - **Test Files Created:**
-  - `src/components/dashboard/decision-card.test.tsx` - 11 tests
+  - `src/components/dashboard/decision-card.test.tsx` - 19 tests
   - `src/components/dashboard/data-panel.test.tsx` - 18 tests
   - `src/components/dashboard/nutrition-panel.test.tsx` - 12 tests
   - `src/components/dashboard/override-toggles.test.tsx` - 18 tests
   - `src/components/calendar/day-cell.test.tsx` - 23 tests
-- **Total Tests Added:** 82 tests across 5 files
+- **Total Tests Added:** 90 tests across 5 files
 - **Why:** Component isolation ensures UI correctness and prevents regressions
 
 ---
@@ -902,7 +902,7 @@ P4.* UX Polish ────────> After core functionality complete
 - [x] **metrics.ts** - Complete with 18 tests (metrics collection, counters, gauges, histograms, Prometheus format) (P2.16)
 
 ### Components
-- [x] **DecisionCard** - Displays decision status, icon, and reason
+- [x] **DecisionCard** - Displays decision status, icon, reason with color-coded backgrounds (RED/YELLOW/GREEN per status)
 - [x] **DataPanel** - Shows body battery, HRV, intensity data
 - [x] **NutritionPanel** - Shows seeds, carbs, keto guidance
 - [x] **OverrideToggles** - Toggle buttons for flare/stress/sleep/pms
@@ -952,7 +952,7 @@ P4.* UX Polish ────────> After core functionality complete
 - [x] **P3.7: Error Handling Improvements** - Replaced console.error with structured pino logger across API routes, added key event logging (Period logged, Override toggled, Decision calculated, Auth failure), 3 new tests in auth-middleware.test.ts
 - [x] **P3.8: Loading States** - Complete with skeleton components (DecisionCardSkeleton, DataPanelSkeleton, NutritionPanelSkeleton, MiniCalendarSkeleton, OverrideTogglesSkeleton, CycleInfoSkeleton, DashboardSkeleton), 29 tests in skeletons.test.tsx; loading.tsx files for all routes (dashboard, calendar, history, plan, settings); shimmer animations matching spec requirements
 - [x] **P3.9: Token Expiration Warnings** - Complete with 10 new tests in email.test.ts, 10 new tests in garmin-sync/route.test.ts; sends warnings at 14 and 7 days before expiry
-- [x] **P3.11: Missing Component Tests** - Complete with 82 tests across 5 component test files (DecisionCard: 11, DataPanel: 18, NutritionPanel: 12, OverrideToggles: 18, DayCell: 23)
+- [x] **P3.11: Missing Component Tests** - Complete with 90 tests across 5 component test files (DecisionCard: 19, DataPanel: 18, NutritionPanel: 12, OverrideToggles: 18, DayCell: 23)
 
 ### P4: UX Polish and Accessibility
 - [x] **P4.1: Dashboard Onboarding Banners** - Complete with OnboardingBanner component (16 tests), dashboard integration (5 new tests)
@@ -977,7 +977,7 @@ Analysis of all specs vs implementation revealed these gaps:
 | Garmin sync structured logging | observability.md | **COMPLETE** | Added sync start/complete/failure logging |
 | Email sent/failed logging | observability.md | **COMPLETE** | Email events now logged (info for success, error for failure) with structured data (userId, emailType, success) |
 | Period history UI | cycle-tracking.md | **PENDING** | UI for viewing/editing past periods |
-| Dashboard color-coded backgrounds | dashboard.md | **PENDING** | Phase-based background colors |
+| Dashboard color-coded backgrounds | dashboard.md | **COMPLETE** | DecisionCard shows RED/YELLOW/GREEN backgrounds per status (8 new tests) |
 | Toast notifications | dashboard.md | **PENDING** | Success/error toasts for user actions |
 | CI pipeline | testing.md | **PENDING** | GitHub Actions for test/lint/build |