feat: migrate to DragonflyDB and clean up environment configuration

- Replace Redis with DragonflyDB for better performance and memory efficiency
- Remove redundant environment variables (POSTGRES_*, ENCRYPTION_KEY, OAUTH_SERVICE_URL)
- Consolidate database configuration to use single DB_* variables
- Use JWT_SECRET for both JWT tokens and encryption
- Remove PORT variable redundancy, use BACKEND_PORT consistently
- Clean up docker-compose configurations for dev/prod consistency
- Add DragonflyDB configuration with optimized memory usage
- Remove redis.conf as it's no longer needed
- Update health checks to use Redis-compatible CLI for DragonflyDB
- Add missing VITE_API_URL to production frontend
- Fix GitHub Actions to use correct go.sum path
- Clean up development directories and unused files

frontend/src/global.d.ts

@@ -39,5 +39,23 @@ declare module "*.bmp" {
   export default content;
 }
 
+interface ImportMetaEnv {
+  readonly VITE_API_URL?: string;
+  readonly VITE_DEMO_MODE?: string;
+  readonly VITE_OAUTH_SERVICE_URL?: string;
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}
+
+interface Window {
+  importMetaEnv?: {
+    VITE_API_URL?: string;
+    VITE_DEMO_MODE?: string;
+    VITE_OAUTH_SERVICE_URL?: string;
+  };
+}
+
 // Global build-time constants
 declare const __APP_VERSION__: string;