fc3d: settings API exposes scheduling knobs with bounds validation

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/test_api_settings.py

@@ -82,6 +82,68 @@ async def test_system_stats_shape(client):
         assert status in body["tasks"]
 
 
+# --- FC-3d: scheduling knobs ----------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_get_includes_scheduling_defaults(client):
+    resp = await client.get("/api/settings/import")
+    body = await resp.get_json()
+    assert body["download_schedule_default_seconds"] == 28800
+    assert body["download_event_retention_days"] == 90
+    assert body["download_failure_warning_threshold"] == 5
+
+
+@pytest.mark.asyncio
+async def test_patch_scheduling_defaults(client):
+    resp = await client.patch("/api/settings/import", json={
+        "download_schedule_default_seconds": 7200,
+        "download_event_retention_days": 30,
+        "download_failure_warning_threshold": 3,
+    })
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["download_schedule_default_seconds"] == 7200
+    assert body["download_event_retention_days"] == 30
+    assert body["download_failure_warning_threshold"] == 3
+
+
+@pytest.mark.asyncio
+async def test_patch_rejects_below_min_interval(client):
+    resp = await client.patch(
+        "/api/settings/import",
+        json={"download_schedule_default_seconds": 30},
+    )
+    assert resp.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_patch_rejects_above_max_interval(client):
+    resp = await client.patch(
+        "/api/settings/import",
+        json={"download_schedule_default_seconds": 90000},
+    )
+    assert resp.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_patch_rejects_zero_retention_days(client):
+    resp = await client.patch(
+        "/api/settings/import",
+        json={"download_event_retention_days": 0},
+    )
+    assert resp.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_patch_rejects_zero_failure_threshold(client):
+    resp = await client.patch(
+        "/api/settings/import",
+        json={"download_failure_warning_threshold": 0},
+    )
+    assert resp.status_code == 400
+
+
 @pytest.mark.asyncio
 async def test_system_stats_integrity_counts(client, db):
     from backend.app.models import ImageRecord