implicit: implement Implicit 9.1 - document all environment variables

- Created .env.example with all required environment variables
- Documented API, WebSocket, Stream, Upload configurations
- Documented application configuration (name, version)
- Documented debug mode and MSW settings
- Documented optional variables (FCM, Sentry)
- All variables include descriptions and default values
- Helps developers set up the project correctly

apps/web/.env.example

@@ -0,0 +1,42 @@
+# Veza Frontend Environment Variables
+# Copy this file to .env and update with your values
+
+# API Configuration
+# Base URL for the REST API (can be absolute URL or path starting with /)
+VITE_API_URL=/api/v1
+
+# WebSocket Configuration
+# WebSocket URL for real-time features (can be absolute URL or path starting with /)
+VITE_WS_URL=/ws
+
+# Stream Server Configuration
+# Stream server URL for audio streaming (can be absolute URL or path starting with /)
+VITE_STREAM_URL=/stream
+
+# Upload Configuration
+# Upload endpoint URL (can be absolute URL or path starting with /)
+VITE_UPLOAD_URL=/upload
+
+# Application Configuration
+# Application name
+VITE_APP_NAME=Veza
+
+# API Version
+# API version to use
+VITE_API_VERSION=v1
+
+# Debug Mode
+# Enable debug logging (true/1 or false/0)
+VITE_DEBUG=false
+
+# Mock Service Worker
+# Enable MSW for API mocking in development (true/1 or false/0)
+VITE_USE_MSW=0
+
+# Firebase Cloud Messaging
+# VAPID key for push notifications (optional)
+# VITE_FCM_VAPID_KEY=your-vapid-key-here
+
+# Sentry Error Tracking
+# Sentry DSN for error tracking (optional)
+# VITE_SENTRY_DSN=https://your-sentry-dsn@sentry.io/project-id