feat(workouts): add swipe-to-delete with gesture handler and pull-to-refresh

AGENTS.md

@@ -25,7 +25,7 @@ src/
   navigation/                # React Navigation (RootNav, TabNav, feature stacks)
   db/                        # Drizzle schema, client, relations, operations
   providers/                 # DatabaseProvider, SettingsProvider (MMKV)
-  utils/                     # formatTime, calculateSwolf, etc.
+  utils/                     # formatTime, calculateSwolf, uuid, etc.
   constants/                 # strokes, poolLengths, colors
   types/                     # workout.ts, common.ts
   modules/watch-connectivity/# Expo native module bridging WCSession
@@ -45,7 +45,7 @@ targets/watch/               # Apple Watch app (Swift/SwiftUI) — survives preb
 - Lives in `targets/watch/`, NOT in `ios/` — survives `expo prebuild --clean`
 - Config: `targets/watch/expo-target.config.js`
 - Build: open `ios/SwimBuddy.xcworkspace` in Xcode, select Watch scheme
-- Uses App Groups (`group.nl.guido-it.swimbuddy`) for data sharing via UserDefaults
+- Uses App Groups (`group.nl.guido-it.swimbuddy`) for data sharing
 - WCSession for real-time messaging, `transferUserInfo` for reliable offline sync
 - HealthKit for swim workout tracking (indoor swimming)
 - Swift types `StoredWorkout`, `StoredSet`, `CompletedLap` in `WorkoutManager.swift`
@@ -53,12 +53,40 @@ targets/watch/               # Apple Watch app (Swift/SwiftUI) — survives preb
 ## Database
 
 - **expo-sqlite** + **Drizzle ORM** (SQLite dialect, expo driver)
-- Schema: `src/db/schema.ts` — 4 tables: templates, workouts, sets, laps
+- Schema: `src/db/schema.ts` — tables: templates, workouts, sets, laps
 - Relations: `src/db/relations.ts`
 - CRUD: `src/db/operations.ts`
 - Client: `src/db/client.ts` — exports `db` and `DATABASE_NAME`
 - Migrations in `drizzle/` — generated by `npx drizzle-kit generate`
 
+## WCSession Gotchas (Critical)
+
+These are hard-won bugs that will waste hours if rediscovered:
+
+- **`NSNull` crashes `sendMessage`**: JS `null` becomes `NSNull` in ObjC, causing `WCErrorCodePayloadUnsupportedTypes` (Code 7010). Always strip `null`/`undefined` values before sending via `cleanForWCSession()`.
+- **Two delegate methods conflict**: Having both `session(_:didReceiveMessage:)` AND `session(_:didReceiveMessage:replyHandler:)` on the same delegate causes iOS to deliver neither. Watch uses `didReceiveMessage` (no replyHandler); phone uses `didReceiveMessage:replyHandler:` for bidirectional sync.
+- **`isReachable` is unreliable**: Only `true` when both apps are foreground. Check `session.activationState == .activated` instead for connection readiness.
+- **Phone `sendMessage` must use `replyHandler: nil`**: Otherwise JS thread blocks waiting for a reply that watch never sends. Use fire-and-forget for workout plans; use `transferUserInfo` for data sync.
+- **Watch `suiteName` vs `UserDefaults.standard`**: Watch only needs local storage, so use `UserDefaults.standard` — the App Groups suite name is only needed for phone↔watch shared data.
+- **Phone `pendingEvents` polling**: Phone polls `pollEvents()` every 2s because Expo Modules' `sendEvent` API doesn't work on `AppContext`. Watch data arrives via `didReceiveUserInfo` delegate → stored in `pendingEvents` array.
+
+## Watch ↔ Phone Data Flow
+
+- **Phone → Watch**: `sendMessage` with workout plan (fire-and-forget, promise resolves immediately with `["status":"sent"]`)
+- **Watch → Phone**: `transferUserInfo` with completed workout data (reliable, works in background)
+- **Phone receives**: `pollEvents()` called from JS every 2s, `saveWatchCompletedWorkout()` writes to SQLite
+
+## UI Conventions
+
+- Swipe-to-delete on lists uses `SwipeableRow` component (`react-native-gesture-handler`)
+- BuilderScreen pool length is a 25m/50m toggle (not read-only from settings)
+- Templates and Stats features removed from navigation (DB schema preserved but UI deleted)
+- Ionicons used for bottom tab icons (`@expo/vector-icons`)
+
+## NativeWind v5 TextInput Crash
+
+`react-native-css` has a bug where the `textAlign` mapping on `TextInput` causes a crash (`path.split` on boolean `true`). The fix is in `src/utils/` — don't remove the workaround without testing TextInput rendering.
+
 ## Gotchas
 
 - `metro.config.js` has `.sql` in `sourceExts` — required for Drizzle migration imports