feat: support shared-workspace file flow for matrix

.env.example

@@ -5,13 +5,16 @@ TELEGRAM_BOT_TOKEN=your_bot_token_here
 MATRIX_HOMESERVER=https://matrix.org
 MATRIX_USER_ID=@bot:matrix.org
 MATRIX_PASSWORD=your_password_here
-
-# Lambda Platform
-LAMBDA_PLATFORM_URL=http://localhost:8000
-LAMBDA_SERVICE_TOKEN=your_service_token_here
-AGENT_WS_URL=ws://127.0.0.1:8000/agent_ws/
-AGENT_BASE_URL=http://127.0.0.1:8000
 MATRIX_PLATFORM_BACKEND=real
 
-# Режим работы: "mock" или "production"
-PLATFORM_MODE=mock
+# Shared workspace contract
+SURFACES_WORKSPACE_DIR=/workspace
+
+# Compose-local platform-agent route
+AGENT_WS_URL=ws://platform-agent:8000/v1/agent_ws/{chat_id}/
+AGENT_BASE_URL=http://platform-agent:8000
+
+# platform-agent provider
+PROVIDER_MODEL=openai/gpt-4o-mini
+PROVIDER_URL=https://openrouter.ai/api/v1
+PROVIDER_API_KEY=sk-or-...