feat(phase-1): implement Foundation & Kiosk UI

- Add Flask backend with SocketIO for real-time updates
- Implement sensor service with mock data generation
- Create Dashboard UI with rainfall, voltage, status displays
- Create Settings UI with station, network, ADC, sensor configuration
- Create Calibration UI with live ADC readings and rainfall reset
- Touch-optimized interface with 64px touch targets for 7" display

Implements: DASH-01 through DASH-09, UI-01 through UI-03,
SETT-01 through SETT-08, CAL-01 through CAL-04, BACK-01 through BACK-03

.planning/phases/01-foundation-kiosk-ui/01-PLAN.md

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+---
+phase: 1
+plan: 1
+name: Foundation & Kiosk UI
+type: execution
+autonomous: true
+wave: 1
+depends_on: []
+
+requirements:
+  - DASH-01
+  - DASH-02
+  - DASH-03
+  - DASH-04
+  - DASH-05
+  - DASH-06
+  - DASH-07
+  - DASH-08
+  - DASH-09
+  - UI-01
+  - UI-02
+  - UI-03
+  - SETT-01
+  - SETT-02
+  - SETT-03
+  - SETT-04
+  - SETT-05
+  - SETT-06
+  - SETT-07
+  - SETT-08
+  - CAL-01
+  - CAL-02
+  - CAL-03
+  - CAL-04
+  - BACK-01
+  - BACK-02
+  - BACK-03
+---
+
+# Phase 1 Plan: Foundation & Kiosk UI
+
+## Objective
+
+Build the foundational Flask backend with real-time sensor data API and the 7" touchscreen kiosk UI (port 8080) displaying rainfall readings, voltage status, date/time, station ID, communication status, and software version. Include Settings and Calibration menus for configuration access.
+
+## Context
+
+This is the first vertical slice — each layer works end-to-end before adding persistence or network transmission. The research selected Flask + Flask-SocketIO + Bootstrap for Pi Zero 2 W performance.
+
+## Success Criteria
+
+1. User can view current rainfall readings (Today, Hourly, MAR Accumulated, Yearly Accumulated) on the dashboard
+2. User can view solar voltage and battery voltage with status indicator (HIGH/NORMAL/LOW) on the dashboard
+3. User can view current date/time (HH:MM:SS DD-MM-YYYY) and station ID on the dashboard
+4. User can view communication status (signal strength, connection status) and software version on the dashboard
+5. User can navigate between Dashboard, Settings, and Calibration menus via main menu
+6. User can access and modify station info, date/time, network settings, sensor thresholds, and ADC configuration
+7. User can view live ADC channel readings and reset rainfall counters in calibration view
+8. Dashboard updates automatically with real-time sensor data
+9. Touch interface responds with large touch targets (minimum 48px) optimized for 7" 1024x600 display
+
+---
+
+## Tasks
+
+### Task 1: Initialize Project Structure & Dependencies
+**Type:** auto  
+**Description:** Create project directory structure and requirements.txt  
+**Verification:** `ls -la src/` shows proper structure, `pip install -r requirements.txt` succeeds
+
+---
+
+### Task 2: Create Flask Backend with SocketIO
+**Type:** auto  
+**Description:** Set up Flask app with SocketIO, routes folder structure, and base configuration  
+**Verification:** `python src/app.py` starts server on port 8080, `/api/status` returns JSON
+
+---
+
+### Task 3: Implement Sensor Service with Mock Data
+**Type:** auto  
+**Description:** Create sensor service that generates realistic mock rainfall/voltage readings  
+**Verification:** `/api/sensors` returns valid sensor data structure with all fields
+
+---
+
+### Task 4: Create Status API Endpoint
+**Type:** auto  
+**Description:** Implement `/api/status` returning station ID, date/time, software version  
+**Verification:** API returns all required status fields
+
+---
+
+### Task 5: Create Settings API Endpoints
+**Type:** auto  
+**Description:** Implement `/api/settings` GET/POST for station, network, ADC, thresholds  
+**Verification:** GET returns settings, POST updates settings, data persists to JSON
+
+---
+
+### Task 6: Create Calibration API Endpoints
+**Type:** auto  
+**Description:** Implement `/api/calibration` for live ADC readings and rainfall reset  
+**Verification:** Returns live ADC values, reset endpoint clears rainfall counters
+
+---
+
+### Task 7: Build Dashboard HTML/CSS/JS
+**Type:** auto  
+**Description:** Create main dashboard template with rainfall, voltage, status displays  
+**Verification:** Dashboard renders with all required elements, responsive to 1024x600
+
+---
+
+### Task 8: Implement Real-Time Updates via SocketIO
+**Type:** auto  
+**Description:** Frontend connects to SocketIO, receives live sensor updates every second  
+**Verification:** Dashboard auto-updates without page refresh
+
+---
+
+### Task 9: Build Settings UI
+**Type:** auto  
+**Description:** Create settings pages for station info, date/time, network, ADC config, thresholds  
+**Verification:** All settings accessible and modifiable through UI forms
+
+---
+
+### Task 10: Build Calibration UI
+**Type:** auto  
+**Description:** Create calibration view showing live ADC readings with channel info  
+**Verification:** Shows 4 channels with type, ADC value, datum, calculated reading
+
+---
+
+### Task 11: Add Touch-Optimized Navigation
+**Type:** auto  
+**Description:** Implement main menu with large touch targets (64px), back buttons, 7" optimized CSS  
+**Verification:** Navigation works with touch, all targets >= 48px
+
+---
+
+### Task 12: Final Integration & Testing
+**Type:** auto  
+**Description:** Verify all 27 requirements met, test server startup, verify all pages load  
+**Verification:** All requirements traceable, no console errors, server stable