feat: Telegram settings in DB with UI edit and test send

Store notification_channels (migration 004), effective config DB over env,
PUT/test API endpoints, Settings form, and pass db session into ingest notify.

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

backend/tests/test_settings_api.py

@@ -1,6 +1,10 @@
-"""GET /api/v1/settings/notifications"""
+"""GET/PUT/POST /api/v1/settings/notifications"""
 
-from app.services.telegram_notify import get_settings
+from unittest.mock import patch
+
+from app.config import get_settings
+from app.models.notification_channel import NotificationChannel
+from app.services.notification_settings import get_effective_telegram_config
 
 
 def test_get_notification_settings_masks_secrets(jwt_headers, client, monkeypatch):
@@ -18,4 +22,70 @@ def test_get_notification_settings_masks_secrets(jwt_headers, client, monkeypatc
     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"]
+
+
+def test_put_telegram_settings_persists_db(jwt_headers, client, db_session, monkeypatch):
+    monkeypatch.setenv("TELEGRAM_ENABLED", "false")
+    monkeypatch.setenv("TELEGRAM_BOT_TOKEN", "")
+    monkeypatch.setenv("TELEGRAM_CHAT_ID", "")
+    monkeypatch.setenv("TELEGRAM_MIN_SEVERITY", "high")
+    get_settings.cache_clear()
+
+    response = client.put(
+        "/api/v1/settings/notifications/telegram",
+        headers=jwt_headers,
+        json={
+            "enabled": True,
+            "min_severity": "warning",
+            "bot_token": "1234567890:TESTTOKEN",
+            "chat_id": "999001",
+        },
+    )
+    assert response.status_code == 200
+    body = response.json()
+    assert body["source"] == "db"
+    assert body["enabled"] is True
+    assert body["min_severity"] == "warning"
+
+    row = db_session.get(NotificationChannel, "telegram")
+    assert row is not None
+    assert row.bot_token == "1234567890:TESTTOKEN"
+    assert row.chat_id == "999001"
+
+    cfg = get_effective_telegram_config(db_session)
+    assert cfg.source == "db"
+    assert cfg.min_severity == "warning"
+
+
+def test_post_telegram_test_success(jwt_headers, client, db_session, monkeypatch):
+    monkeypatch.setenv("TELEGRAM_ENABLED", "true")
+    monkeypatch.setenv("TELEGRAM_BOT_TOKEN", "tok")
+    monkeypatch.setenv("TELEGRAM_CHAT_ID", "1")
+    get_settings.cache_clear()
+
+    db_session.add(
+        NotificationChannel(
+            channel="telegram",
+            enabled=True,
+            min_severity="warning",
+            bot_token="1234567890:ABCDEF",
+            chat_id="2843230",
+        )
+    )
+    db_session.commit()
+
+    with patch("app.api.v1.settings.send_telegram_test_message") as mock_test:
+        response = client.post("/api/v1/settings/notifications/telegram/test", headers=jwt_headers)
+    assert response.status_code == 200
+    assert response.json()["ok"] is True
+    mock_test.assert_called_once()
+
+
+def test_post_telegram_test_not_configured(jwt_headers, client, monkeypatch):
+    monkeypatch.setenv("TELEGRAM_ENABLED", "false")
+    monkeypatch.setenv("TELEGRAM_BOT_TOKEN", "")
+    monkeypatch.setenv("TELEGRAM_CHAT_ID", "")
+    get_settings.cache_clear()
+
+    response = client.post("/api/v1/settings/notifications/telegram/test", headers=jwt_headers)
+    assert response.status_code == 400