init: surfaces-bot — Telegram & Matrix prototype

- Surface Protocol: unified IncomingMessage/OutgoingUI/ChatContext
- Telegram: Forum Topics (group + topics per chat)
- Matrix: Space + rooms per chat
- MockPlatformClient with PlatformClient Protocol
- docs: surface-protocol, telegram/matrix specs, api-contract, claude-code-guide
- project scaffold: src/, tests/, pyproject.toml

Co-Authored-By: Claude Sonnet 4-6 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,14 @@
+# Telegram
+TELEGRAM_BOT_TOKEN=your_bot_token_here
+
+# Matrix
+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
+
+# Режим работы: "mock" или "production"
+PLATFORM_MODE=mock