add Telegram alerts: qualified setups, S/R proximity, score drops, daily digest

Closes the action loop — instead of polling the dashboard, the platform pushes
actionable signals to Telegram. New hourly 'alerts' job dispatches four
toggleable triggers, deduped via a new alert_log table (cooldown-based for
qualified/S-R/digest, watermark-based for score deterioration). Admin → Settings
gains a Telegram panel (write-only bot token, chat ID, per-trigger toggles, Send
Test). Credentials follow DB > env precedence (TELEGRAM_BOT_TOKEN / _CHAT_ID).

Backend: alert_service + AlertLog model + migration 005, scheduler job, admin
endpoints/schema. Frontend: AlertSettings panel, hooks, api, types.

Deploy: run alembic upgrade (new alert_log table).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/config.py

@@ -37,11 +37,16 @@ class Settings(BaseSettings):
     # Fundamentals Provider — Alpha Vantage (optional fallback)
     alpha_vantage_api_key: str = ""
 
+    # Alerts — Telegram (optional env fallback; can also be set in Admin)
+    telegram_bot_token: str = ""
+    telegram_chat_id: str = ""
+
     # Scheduled Jobs
     data_collector_frequency: str = "daily"
     sentiment_poll_interval_minutes: int = 30
     fundamental_fetch_frequency: str = "daily"
     rr_scan_frequency: str = "daily"
+    alerts_frequency: str = "hourly"
     fundamental_rate_limit_retries: int = 3
     fundamental_rate_limit_backoff_seconds: int = 15