feat(provenance): /api/provenance image + post endpoints

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

tests/test_api_provenance.py

@@ -0,0 +1,84 @@
+from datetime import UTC, datetime
+
+import pytest
+
+from backend.app import create_app
+from backend.app.models import (
+    Artist,
+    ImageProvenance,
+    ImageRecord,
+    Post,
+    Source,
+)
+
+pytestmark = pytest.mark.integration
+
+
+@pytest.fixture
+async def app():
+    return create_app()
+
+
+@pytest.fixture
+async def client(app):
+    async with app.test_client() as c:
+        yield c
+
+
+async def _seed_full(db):
+    rec = ImageRecord(
+        path="/images/p/1.jpg", sha256="p" + "0" * 63,
+        size_bytes=1, mime="image/jpeg", width=1, height=1,
+        origin="imported_filesystem", integrity_status="unknown",
+    )
+    artist = Artist(name="Alice", slug="alice")
+    db.add_all([rec, artist])
+    await db.flush()
+    source = Source(artist_id=artist.id, platform="patreon",
+                    url="https://patreon.test/alice")
+    db.add(source)
+    await db.flush()
+    post = Post(source_id=source.id, external_post_id="555",
+                post_url="https://patreon.test/p/555", post_title="Set 1",
+                post_date=datetime(2023, 8, 1, tzinfo=UTC),
+                description="<p>hi</p>", attachment_count=2)
+    db.add(post)
+    await db.flush()
+    db.add(ImageProvenance(image_record_id=rec.id, post_id=post.id,
+                           source_id=source.id))
+    await db.flush()
+    await db.commit()
+    return rec.id, post.id
+
+
+@pytest.mark.asyncio
+async def test_image_provenance_endpoint(client, db):
+    image_id, post_id = await _seed_full(db)
+    resp = await client.get(f"/api/provenance/image/{image_id}")
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["image_id"] == image_id
+    assert len(body["provenance"]) == 1
+    assert body["provenance"][0]["post"]["id"] == post_id
+
+
+@pytest.mark.asyncio
+async def test_image_provenance_404(client):
+    resp = await client.get("/api/provenance/image/999999")
+    assert resp.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_post_provenance_endpoint(client, db):
+    _, post_id = await _seed_full(db)
+    resp = await client.get(f"/api/provenance/post/{post_id}")
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["post"]["id"] == post_id
+    assert body["artist"]["slug"] == "alice"
+
+
+@pytest.mark.asyncio
+async def test_post_provenance_404(client):
+    resp = await client.get("/api/provenance/post/999999")
+    assert resp.status_code == 404