feat: Phase 1 Foundation & Dashboard implementation

- Core infrastructure: Zustand store, API client with mock fallback
- Mode detection: Port 8080 (kiosk) / 9090 (remote)
- Dashboard components: RainfallCard, ClockDisplay, CommStatus
- Header components: VoltageDisplay, BatteryStatus, LoginIndicator
- Data polling with visibility awareness
- Bundle size: ~100KB gzipped

Also adds README.md and WIKI.md documentation

.planning/phases/01-foundation-dashboard/01-03-SUMMARY.md

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+# Plan 03 Summary - Dashboard View
+
+**Plan:** 03  
+**Phase:** 01-foundation-dashboard  
+**Completed:** 2026-03-13
+
+---
+
+## Tasks Completed
+
+### Task 1: RainfallCard Component
+- Created `src/app/components/RainfallCard.tsx`:
+  - Props: label, value, variant (today/hourly/monthly/yearly)
+  - Color-coded: Today (blue), Hourly (cyan), MAR (green), Yearly (purple)
+  - Large value display with unit
+  - CloudRain icon from Lucide
+
+### Task 2: ClockDisplay Component
+- Created `src/app/components/ClockDisplay.tsx`:
+  - Real-time clock (HH:MM:SS) updating every second
+  - Date display (YYYY-MM-DD)
+  - Proper cleanup on unmount
+
+### Task 3: CommStatus Component
+- Created `src/app/components/CommStatus.tsx`:
+  - Props: asu, dBm, percentage
+  - Color-coded signal quality indicator
+  - Shows: good (green), fair (yellow), poor (red)
+
+### Task 4: RainfallView Dashboard
+- Updated `src/app/components/views/RainfallView.tsx`:
+  - Uses sensor store for real-time data
+  - 4 rainfall cards in responsive grid
+  - ClockDisplay and CommStatus integrated
+  - Last update timestamp
+
+### Task 5: Dual-Mode Responsive Layout
+- Implemented port-based mode detection
+- Kiosk (1024x600): 2-column grid, compact padding
+- Remote (Full HD): 4-column grid, more spacing
+
+---
+
+## Files Created/Modified
+
+| File | Status |
+|------|--------|
+| src/app/components/RainfallCard.tsx | Created |
+| src/app/components/ClockDisplay.tsx | Created |
+| src/app/components/CommStatus.tsx | Created |
+| src/app/components/views/RainfallView.tsx | Modified |
+
+---
+
+## Component Usage
+
+```tsx
+// RainfallCard
+<RainfallCard label="Today" value={12.5} variant="today" />
+
+// ClockDisplay
+<ClockDisplay />
+
+// CommStatus
+<CommStatus asu={15} dBm={-75} percentage={50} />
+
+// In RainfallView
+<RainfallCard
+  label={item.label}
+  value={item.value}
+  variant={item.variant}
+/>
+```
+
+---
+
+## Responsive Behavior
+
+- **Kiosk (port 8080)**: 2-column grid, smaller padding
+- **Remote (port 9090)**: 4-column grid, expanded layout
+
+---
+
+## Notes
+
+- Dashboard updates in real-time from sensor store
+- All components connect to Zustand store
+- Dual-mode display responds to port number
+- Touch-friendly with adequate hit areas