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

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

backend/tests/test_settings_api.py

@@ -0,0 +1,21 @@
+"""GET /api/v1/settings/notifications"""
+
+from app.services.telegram_notify import get_settings
+
+
+def test_get_notification_settings_masks_secrets(jwt_headers, client, monkeypatch):
+    monkeypatch.setenv("TELEGRAM_ENABLED", "true")
+    monkeypatch.setenv("TELEGRAM_BOT_TOKEN", "1234567890:ABCDEFghij")
+    monkeypatch.setenv("TELEGRAM_CHAT_ID", "2843230")
+    monkeypatch.setenv("TELEGRAM_MIN_SEVERITY", "warning")
+    get_settings.cache_clear()
+
+    response = client.get("/api/v1/settings/notifications", headers=jwt_headers)
+    assert response.status_code == 200
+    body = response.json()
+    assert body["telegram"]["enabled"] is True
+    assert body["telegram"]["configured"] is True
+    assert body["telegram"]["min_severity"] == "warning"
+    assert body["telegram"]["source"] == "env"
+    assert body["telegram"]["bot_token_hint"].endswith("ghij")
+    assert "1234567890" not in body["telegram"]["bot_token_hint"]