Fix InviteOneAcceptView migration fence; remove USE_DEXIE_DB dependency

- Remove USE_DEXIE_DB import from app.ts constants
- Update InviteOneAcceptView to use PlatformServiceMixin pattern
- Remove legacy Dexie database access code
- Move WORKER_ONLY_DATABASE_IMPLEMENTATION.md to doc/ directory
- Remerge changes in router/index.ts

Fixes Electron build failure caused by missing USE_DEXIE_DB export.

src/main.capacitor.ts

@@ -72,12 +72,11 @@ const handleDeepLink = async (data: { url: string }) => {
     await deepLinkHandler.handleDeepLink(data.url);
   } catch (error) {
     logger.error("[DeepLink] Error handling deep link: ", error);
-    handleApiError(
-      {
-        message: error instanceof Error ? error.message : safeStringify(error),
-      } as AxiosError,
-      "deep-link",
-    );
+    let message: string = error instanceof Error ? error.message : safeStringify(error);
+    if (data.url) {
+      message += `\nURL: ${data.url}`;
+    }
+    handleApiError({ message } as AxiosError, "deep-link");
   }
 };