basic working app currently wworking on the sync to work

plan.md

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+Expo (React Native) + WatermelonDB
+Aspect	Why
+Platforms	Single codebase → iOS, Android, Web (Expo for Web)
+Offline-first	WatermelonDB is built for this - local SQLite, reactive queries, lazy loading
+Sync	Custom sync adapter to your Postgres API (REST/GraphQL)
+Team fit	React/TypeScript native
+UI	Matches your spec (React Native components, Reanimated for animations)
+Alternative: Expo + PowerSync
+- Newer, SQL-based local DB with built-in sync protocol
+- Handles conflict resolution, partial replication
+- Requires PowerSync service (self-hosted or cloud) between app and your Postgres
+Architecture Overview
+┌─────────────┐     ┌──────────────┐     ┌─────────────┐
+│   Expo App  │────▶│ WatermelonDB │────▶│  Your API   │
+│ (iOS/Android│     │  (SQLite)    │     │  (Postgres) │
+│    Web)     │◀───▶│  + Sync      │◀───▶│             │
+└─────────────┘     └──────────────┘     └─────────────┘
+Key Libraries
+- Navigation: Expo Router (file-based, works on web)
+- State: WatermelonDB (no Redux needed - DB is source of truth)
+- UI: React Native Paper or Tamagui (cross-platform components)
+- Date/Time: @react-native-community/datetimepicker + date-fns
+- Forms: React Hook Form + Zod validation
+Sync Strategy (Custom API)
+1. WatermelonDB synchronize() pulls changes since last sync token
+2. Your API exposes /sync endpoint accepting lastPulledAt cursor
+3. Returns { changes: [...], serverTimestamp }
+4. Push local changes via /sync/push batch endpoint
+5. Handle conflicts: last-write-wins or user resolution