Add system memory monitoring, Bedrock support, and Discord integrations

- Add CPU/GPU memory monitoring endpoint and frontend widget
- Add Amazon Bedrock model support (API key / inference profiles) plus model selector entries
- Add Discord weather/laundry notification job (JMA forecast + LLM-generated message)
- Add Discord bot that replies to mentions via the configured LLM, with weather-aware context
- Add scheduled "useless tips" job with separate webhook and quiet-hours skip
- Switch FastAPI startup to lifespan handler, log viewer, markdown rendering, and toast UI additions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/core/config.py

@@ -7,3 +7,35 @@ DATABASE_URL: str = os.getenv("DATABASE_URL", "sqlite:///./playchat.db")
 DEFAULT_MODEL: str = os.getenv("DEFAULT_MODEL", "gpt-4o")
 MEMORY_SUMMARIZE_THRESHOLD: int = int(os.getenv("MEMORY_SUMMARIZE_THRESHOLD", "20"))
 CORS_ORIGINS: list[str] = os.getenv("CORS_ORIGINS", "http://localhost:5173").split(",")
+DEBUG: bool = os.getenv("DEBUG", "false").lower() in ("1", "true", "yes")
+
+# Amazon Bedrock
+# AWS_BEARER_TOKEN_BEDROCK (API key方式) / AWS_REGION_NAME は
+# LiteLLM が os.environ から直接読み取るため、.env に書くだけで自動的に有効になる
+AWS_BEARER_TOKEN_BEDROCK: str | None = os.getenv("AWS_BEARER_TOKEN_BEDROCK")
+AWS_REGION_NAME: str = os.getenv("AWS_REGION_NAME", "us-east-1")
+
+# 天気予報 → Discord 通知
+DISCORD_WEBHOOK_URL: str | None = os.getenv("DISCORD_WEBHOOK_URL")
+WEATHER_AREA_CODE: str = os.getenv("WEATHER_AREA_CODE", "120000")  # 千葉県
+WEATHER_AREA_KEYWORD: str = os.getenv("WEATHER_AREA_KEYWORD", "北西部")  # 市川市は千葉県北西部
+WEATHER_NOTIFY_HOUR: int = int(os.getenv("WEATHER_NOTIFY_HOUR", "22"))
+WEATHER_NOTIFY_MINUTE: int = int(os.getenv("WEATHER_NOTIFY_MINUTE", "0"))
+# 通知メッセージをLLMで生成する場合に使うモデル（未設定ならDEFAULT_MODELを使用）
+WEATHER_NOTIFY_MODEL: str | None = os.getenv("WEATHER_NOTIFY_MODEL")
+
+# Discord Bot（メンションへの自動返信用）
+DISCORD_BOT_TOKEN: str | None = os.getenv("DISCORD_BOT_TOKEN")
+DISCORD_BOT_SYSTEM_PROMPT: str = os.getenv(
+    "DISCORD_BOT_SYSTEM_PROMPT",
+    "あなたは「お天気アプリ」という名前のDiscord Botです。"
+    "天気や洗濯指数の質問には親しみやすく簡潔に答え、"
+    "雑談にも気さくに応じてください。絵文字を適度に使って親しみやすい口調で話します。",
+)
+
+# どうでもいいTipsを定期的にDiscordへ投稿する機能
+USELESS_TIPS_ENABLED: bool = os.getenv("USELESS_TIPS_ENABLED", "false").lower() in ("1", "true", "yes")
+USELESS_TIPS_INTERVAL_HOURS: int = int(os.getenv("USELESS_TIPS_INTERVAL_HOURS", "3"))
+USELESS_TIPS_MODEL: str | None = os.getenv("USELESS_TIPS_MODEL")
+# 未設定なら天気通知と同じ DISCORD_WEBHOOK_URL を使う
+DISCORD_WEBHOOK_URL_TIPS: str | None = os.getenv("DISCORD_WEBHOOK_URL_TIPS") or os.getenv("DISCORD_WEBHOOK_URL")