Native Android home screen widget

[cnighswonger]

Summary

A native Android home screen widget that displays current weather conditions from a Kanfei station. Consumes data from either the REST API (#30) or the push export JSON (#29).

Depends on: #28 (JSON schema), and at least one of #29 (push) or #30 (REST)

Features

MVP

• Home screen widget (resizable, minimum 2x1 cells)
• Current temperature, humidity, wind speed/direction, conditions
• Configurable data source URL (REST endpoint or static JSON URL)
• Auto-refresh on configurable interval (default: 5 min)
• Tap widget to open full detail view (in-app or browser to dashboard)

Nice to have

• Multiple widget sizes (2x1 compact, 4x2 detailed, 4x4 full)
• Multiple station support (one widget per station)
• Wind direction compass graphic
• Daily high/low
• Rain accumulation
• "Last updated" timestamp
• Dark/light theme (follow system)
• Offline indicator when data is stale

Data source

The widget should work with either:

1. Push JSON URL — fetch a static JSON file from S3/R2/CDN (simplest, works behind NAT)
2. REST API — fetch from /api/v1/current with API key header

Configuration in the widget setup screen:

• Data URL (required)
• API key (optional, for REST mode)
• Station name / display label
• Refresh interval

Technical considerations

• Kotlin, Jetpack Glance (modern widget framework) or RemoteViews (broader compatibility)
• Minimal permissions: INTERNET only
• Battery-conscious: use WorkManager for background refresh, respect battery saver
• Graceful degradation: show last known data + stale indicator when offline
• Material You theming if using Glance

Repository

This should likely be a separate repo (kanfei-android or kanfei-widget) since it's a different build system (Gradle/Kotlin) and release cycle (Play Store).

Priority

Depends on the public data API (#28-#30) being available first. High user value — home screen weather widgets are one of the most common use cases for PWS data.