Add Docker Compose configuration and environment files for local and production setups

- Created docker-compose.docker-local.yml for local testing of frontend and backend services.
- Added .env.development for development environment configuration.
- Introduced .env.docker-local for local Docker environment settings.
- Added .env.production for production environment configuration for Synology deployment.

code/websites/pokedex.online/.env.docker-local

@@ -0,0 +1,22 @@
+# ====================================================================
+# LOCAL DOCKER ENVIRONMENT - Production Build on localhost:8099
+# ====================================================================
+# This file is loaded when building with: vite build --mode docker-local
+# Tests full production build locally in Docker before deploying
+# Frontend: http://localhost:8099
+# Backend: http://localhost:3099
+# ====================================================================
+
+# Discord OAuth Configuration
+VITE_DISCORD_CLIENT_ID=1466544972059775223
+VITE_DISCORD_REDIRECT_URI=http://localhost:8099/oauth/callback
+
+# Challonge OAuth Configuration
+VITE_CHALLONGE_CLIENT_ID=9d40113bdfd802c6fb01137fa9041b23342ce4f100caedad6dee865a486662df
+VITE_CHALLONGE_REDIRECT_URI=http://localhost:8099/oauth/callback
+
+# Application Configuration
+VITE_APP_TITLE=Pokedex Online (Local)
+
+# Debug Mode - Disable for production-like testing
+VITE_DEBUG=false