Fix worker-only database architecture and Vue Proxy serialization

- Implement worker-only database access to eliminate double migrations
- Add parameter serialization in usePlatformService to prevent Capacitor "object could not be cloned" errors
- Fix infinite logging loop with circuit breaker in databaseUtil
- Use dynamic imports in WebPlatformService to prevent worker thread errors
- Add higher-level database methods (getContacts, getSettings) to composable
- Eliminate Vue Proxy objects through JSON serialization and Object.freeze protection

Resolves Proxy(Array) serialization failures and worker context conflicts across Web/Capacitor/Electron platforms.

src/services/PlatformServiceFactory.ts

@@ -19,6 +19,8 @@ import { CapacitorPlatformService } from "./platforms/CapacitorPlatformService";
  */
 export class PlatformServiceFactory {
   private static instance: PlatformService | null = null;
+  private static callCount = 0; // Debug counter
+  private static creationLogged = false; // Only log creation once
 
   /**
    * Gets or creates the singleton instance of PlatformService.
@@ -27,11 +29,20 @@ export class PlatformServiceFactory {
    * @returns {PlatformService} The singleton instance of PlatformService
    */
   public static getInstance(): PlatformService {
+    PlatformServiceFactory.callCount++;
+
     if (PlatformServiceFactory.instance) {
+      // Normal case - return existing instance silently
       return PlatformServiceFactory.instance;
     }
 
+    // Only log when actually creating the instance
     const platform = process.env.VITE_PLATFORM || "web";
+    
+    if (!PlatformServiceFactory.creationLogged) {
+      console.log(`[PlatformServiceFactory] Creating singleton instance for platform: ${platform}`);
+      PlatformServiceFactory.creationLogged = true;
+    }
 
     switch (platform) {
       case "capacitor":
@@ -45,4 +56,14 @@ export class PlatformServiceFactory {
 
     return PlatformServiceFactory.instance;
   }
+
+  /**
+   * Debug method to check singleton usage stats
+   */
+  public static getStats(): { callCount: number; instanceExists: boolean } {
+    return {
+      callCount: PlatformServiceFactory.callCount,
+      instanceExists: PlatformServiceFactory.instance !== null
+    };
+  }
 }