feat(04-01): add openai dependency and AI config

- Add openai package to dependencies in pyproject.toml
- Extend BotConfig with ai_router, ai_api_key, ai_referer attributes
- Load AI settings from environment with sensible defaults

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pyproject.toml

@@ -9,6 +9,7 @@ dependencies = [
     "sqlalchemy",
     "httpx",
     "aiosqlite",
+    "openai",
 ]
 
 [project.optional-dependencies]

src/moai/bot/config.py

@@ -17,12 +17,18 @@ class BotConfig:
         allowed_users: Set of allowed Telegram user IDs. Empty means all users allowed.
         database_url: SQLAlchemy database URL.
         log_level: Logging level string (DEBUG, INFO, WARNING, ERROR).
+        ai_router: AI router service ("requesty" or "openrouter").
+        ai_api_key: API key for the AI router service.
+        ai_referer: HTTP-Referer header for OpenRouter (optional).
     """
 
     bot_token: str
     allowed_users: set[int]
     database_url: str
     log_level: str
+    ai_router: str
+    ai_api_key: str
+    ai_referer: str | None
 
     @classmethod
     def from_env(cls) -> "BotConfig":
@@ -33,6 +39,9 @@ class BotConfig:
             ALLOWED_USERS (optional): Comma-separated Telegram user IDs.
             DATABASE_URL (optional): Database URL, defaults to SQLite.
             LOG_LEVEL (optional): Logging level, defaults to INFO.
+            AI_ROUTER (optional): AI router service, defaults to "requesty".
+            AI_API_KEY (optional): API key for the AI router service.
+            AI_REFERER (optional): HTTP-Referer header for OpenRouter.
 
         Returns:
             BotConfig instance populated from environment.
@@ -56,9 +65,17 @@ class BotConfig:
         database_url = os.environ.get("DATABASE_URL", "sqlite+aiosqlite:///./moai.db")
         log_level = os.environ.get("LOG_LEVEL", "INFO")
 
+        # AI router configuration
+        ai_router = os.environ.get("AI_ROUTER", "requesty")
+        ai_api_key = os.environ.get("AI_API_KEY", "")
+        ai_referer = os.environ.get("AI_REFERER")
+
         return cls(
             bot_token=bot_token,
             allowed_users=allowed_users,
             database_url=database_url,
             log_level=log_level,
+            ai_router=ai_router,
+            ai_api_key=ai_api_key,
+            ai_referer=ai_referer,
         )