refactor: update environment configuration and documentation

- Modified `.env.example` to reflect new API URL structure and added CDN configuration for external storage.
- Updated `.gitignore` to include deployment secrets and certificate files, ensuring sensitive information is not committed.
- Revised `BACKEND_INTEGRATION.md` to clarify authentication methods, replacing Cognito references with Nostr NIP-98.
- Deleted outdated documentation files (`CONTENT-INTEGRATION-COMPLETE.md`, `CURSOR-MCP-SETUP.md`, `FINAL-STATUS.md`, `FIXES-APPLIED.md`, `INDEEHHUB-INTEGRATION.md`, `PROJECT-COMPLETE.md`, `PROJECT-SUMMARY.md`) to streamline project documentation.

These changes enhance the clarity of the environment setup and improve the overall documentation structure for better developer onboarding.

src/utils/nostr.ts

@@ -82,11 +82,10 @@ class NostrService {
   }
 
   /**
-   * Publish a view/watch event
+   * Publish a view/watch event (NIP-XX view tracking — not yet implemented)
    */
-  async publishView(videoEventId: string) {
-    // TODO: Implement NIP-XX for view tracking
-    console.log('Publishing view for:', videoEventId)
+  async publishView(_videoEventId: string) {
+    // View tracking via Nostr not yet implemented
   }
 
   /**