feat: SAC Telegram settings view, notify_problem severity gate, exclusive docs

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/api/v1/settings.py

@@ -0,0 +1,49 @@
+from fastapi import APIRouter, Depends
+from pydantic import BaseModel, Field
+
+from app.auth.jwt_auth import get_current_user
+from app.config import get_settings
+
+router = APIRouter(prefix="/settings", tags=["settings"])
+
+
+def _mask_secret(value: str, *, visible_tail: int = 4) -> str | None:
+    text = value.strip()
+    if not text:
+        return None
+    if len(text) <= visible_tail:
+        return "*" * len(text)
+    return f"{'*' * 8}…{text[-visible_tail:]}"
+
+
+class TelegramSettingsResponse(BaseModel):
+    enabled: bool
+    configured: bool
+    chat_id_hint: str | None = None
+    bot_token_hint: str | None = None
+    min_severity: str
+    source: str = Field(default="env", description="env until UI persistence (notif-12)")
+
+
+class NotificationSettingsResponse(BaseModel):
+    telegram: TelegramSettingsResponse
+
+
+@router.get("/notifications", response_model=NotificationSettingsResponse)
+def get_notification_settings(
+    _user: str = Depends(get_current_user),
+) -> NotificationSettingsResponse:
+    settings = get_settings()
+    token = settings.telegram_bot_token.strip()
+    chat_id = settings.telegram_chat_id.strip()
+    configured = bool(token and chat_id)
+    return NotificationSettingsResponse(
+        telegram=TelegramSettingsResponse(
+            enabled=bool(settings.telegram_enabled and configured),
+            configured=configured,
+            chat_id_hint=_mask_secret(chat_id),
+            bot_token_hint=_mask_secret(token),
+            min_severity=settings.telegram_min_severity,
+            source="env",
+        )
+    )