simplify: Use activeDid-only approach for notifications

- Simplified authentication to use single activeDid instead of complex user management
- Updated plugin interface to require only setActiveDid() method
- Modified API requests to use activeDid as both issuer and recipient
- Streamlined configuration to activeDid: string instead of complex credential object
- Aligned JWT generation with simple DID-based authentication pattern
- Reduced complexity while maintaining security through DID signing

This assumption significantly simplifies the host application integration.

doc/BACKGROUND_DATA_FETCHING_PLAN.md

@@ -3,7 +3,7 @@
 **Author**: Matthew Raymer  
 **Version**: 1.0.0  
 **Created**: 2025-10-02 07:47:04 UTC  
-**Last Updated**: 2025-10-02 10:15:00 UTC  
+**Last Updated**: 2025-10-02 10:45:00 UTC  
 
 ## Overview
 
@@ -70,7 +70,7 @@ class JWTHelper {
 // Background HTTP Worker
 class DataFetchWorker : CoroutineWorker {
     suspend fun doWork(): Result {
-        val jwt = generateJWT(userDid, 60)
+        val jwt = generateJWT(activeDid, 60)
         val headers = mapOf(
             "Authorization" to "Bearer $jwt",
             "Content-Type" to "application/json"
@@ -78,7 +78,7 @@ class DataFetchWorker : CoroutineWorker {
         
         val offersResponse = httpClient.get("$apiServer/api/v2/report/offers") {
             headers { headers.forEach { append(it.key, it.value) } }
-            parameter("recipientDid", userDid)
+            parameter("recipientId", activeDid)  // Use activeDid for recipient filtering
             parameter("afterId", lastKnownOfferId)
         }
         
@@ -118,7 +118,7 @@ class JWTHelper {
 // Background HTTP Task
 class DataFetchTask {
     func fetchData() async {
-        let jwt = generateJWT(userDid: userDid, expiresInSeconds: 60)
+        let jwt = generateJWT(userDid: activeDid, expiresInSeconds: 60)
         var request = URLRequest(url: apiURL)
         request.setValue("Bearer \(jwt)", forHTTPHeaderField: "Authorization")
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
@@ -173,7 +173,7 @@ interface PluginConfig {
     jwtExpirationSeconds: number;
     requestTimeoutMs: number;
     retryAttempts: number;
-    userDid: string;
+    activeDid: string;  // Simplified to single active DID
     lastKnownOfferId?: string;
     lastKnownPlanId?: string;
 }
@@ -203,11 +203,22 @@ interface PluginConfig {
 
 ### Data Persistence
 
-- **Android Room database** for caching API responses
+#### **Platform-Specific Storage Architecture**
-- **iOS Core Data** for persistent storage
+
-- **Web IndexedDB** for web platform caching
+**Android/Electron Platforms:**
-- **TTL enforcement** for cached data freshness
+- **@capacitor-community/sqlite** plugin integration for native SQLite access
-- **SQLite integration** via @capacitor-community/sqlite for unified storage across platforms
+- **Shared plugin database** - Plugin manages its own SQLite database instance
+- **Direct SQL execution** via plugin's `dbExec()` methods for complex queries
+- **Background worker integration** for database operations during content fetch
+
+**Web Platform:**
+- **absurd-sql** for SQLite support in browser (managed by host application)
+- **Plugin delegation pattern** - Plugin provides SQL queries, host executes them
+- **IndexedDB fallback** for basic caching when SQLite unavailable
+
+**iOS Platform:**
+- **Core Data integration** via native Swift implementation
+- **Background task compatibility** with iOS background refresh constraints
 
 ### State Synchronization
 
@@ -243,11 +254,78 @@ Based on TimeSafari's optimization patterns:
 
 ## Integration Points
 
-### Existing Plugin APIs
+### Enhanced Plugin Interface for Host Application Integration
 
-- **Extend** `DailyNotification.configure()` to include API server settings
+#### **Database Integration Patterns**
-- **Add** new methods: `setUserCredentials()`, `fetchActivityData()`, `getCachedData()`
+
-- **Trigger** notifications based on fetched data differences
+**Android/Electron: Plugin-Managed SQLite**
+```typescript
+// Plugin handles database operations directly
+await plugin.configure({
+  dbPath: 'daily_notifications.db',
+  storage: 'shared'
+});
+
+// Plugin provides database access methods
+const results = await plugin.executeContentFetch(config);
+await plugin.cacheContentData(results);
+
+// Host application accesses cached data via plugin
+const cachedData = await plugin.getContentCache();
+```
+
+**Web: Host-Managed Database**
+```typescript
+// Host application manages absurd-sql database
+import { openDatabase } from 'absurd-sql';
+
+const db = await openDatabase('daily_notifications.db');
+
+// Plugin provides SQL queries, host executes them
+const query = await plugin.getContentFetchQuery(apiEndpoint, credentials);
+const results = await db.exec(query);
+
+// Plugin receives results for processing
+await plugin.processContentData(results);
+```
+
+**iOS: Hybrid Approach**
+```typescript
+// Plugin manages Core Data operations on background thread
+await plugin.scheduleContentFetch(config);
+
+// Host application accesses stored data via plugin APIs
+const notificationData = await plugin.getLastNotification();
+const cachedContent = await plugin.getContentHistory();
+```
+
+#### **New Plugin Methods Required**
+
+```typescript
+interface EnhancedDailyNotificationPlugin {
+  // Database configuration
+  configureDatabase(options: {
+    storageType: 'plugin-managed' | 'host-managed';
+    dbPath?: string;
+    encryption?: boolean;
+  }): Promise<void>;
+  
+  // Content fetch with database integration
+  fetchAndStoreContent(config: ContentFetchConfig): Promise<ContentFetchResult>;
+  
+  // Credential management - simplified to activeDid only
+  setActiveDid(activeDid: string): Promise<void>;
+  
+  // Data access for host application
+  getStoredContent(query: string, params?: any[]): Promise<any[]>;
+  clearStoredContent(options?: { olderThan?: number }): Promise<void>;
+  
+  // Background task coordination
+  getBackgroundTaskStatus(): Promise<BackgroundTaskStatus>;
+  pauseBackgroundTasks(): Promise<void>;
+  resumeBackgroundTasks(): Promise<void>;
+}
+```
 
 ### Background Scheduling
 
@@ -343,8 +421,9 @@ GET {apiServer}/api/v2/report/offersToPlansOwnedByMe?afterId={jwtId}&beforeId={j
 
 ### Token Generation
 
-- Accept user DID as input
+- Accept activeDid as input
-- Generate appropriate authentication token based on user's credential type
+- Generate JWT authentication token using DID signing
+- Include activeDid as both issuer (`iss`) and subject (`sub`)
 - Return token for immediate use or caching
 
 ### Request Execution
@@ -374,7 +453,11 @@ GET {apiServer}/api/v2/report/offersToPlansOwnedByMe?afterId={jwtId}&beforeId={j
 - Implement DID-based authentication
 - Integrate API endpoint calls
 - Add response parsing and validation
-- Implement basic caching
+- Implement platform-specific database integration:
+  - **Android/Electron**: Direct @capacitor-community/sqlite integration
+  - **Web**: Plugin delegation pattern with absurd-sql coordination
+  - **iOS**: Core Data background thread integration
+- Implement simplified activeDid-based authentication and API calls
 
 ### Phase 3: Background Integration (Weeks 5-6)