feat(provenance): _artists_for resolves via artist_id (closes vii-b gap)

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

tests/test_gallery_artist_payload.py

@@ -3,13 +3,7 @@ from datetime import UTC, datetime, timedelta
 import pytest
 
 from backend.app import create_app
-from backend.app.models import (
-    Artist,
-    ImageProvenance,
-    ImageRecord,
-    Post,
-    Source,
-)
+from backend.app.models import Artist, ImageRecord, Source
 
 pytestmark = pytest.mark.integration
 
@@ -48,42 +42,6 @@ async def _artist_source(db, name, slug):
     return a, s
 
 
-@pytest.mark.asyncio
-async def test_scroll_artist_via_primary_post(client, db):
-    rec = await _img(db, 1)
-    _, s = await _artist_source(db, "Alice", "alice")
-    post = Post(source_id=s.id, external_post_id="1")
-    db.add(post)
-    await db.flush()
-    rec.primary_post_id = post.id
-    await db.flush()
-    await db.commit()
-
-    resp = await client.get("/api/gallery/scroll?limit=10")
-    assert resp.status_code == 200
-    body = await resp.get_json()
-    item = next(i for i in body["images"] if i["id"] == rec.id)
-    assert item["artist"] == {"name": "Alice", "slug": "alice"}
-
-
-@pytest.mark.asyncio
-async def test_scroll_artist_via_provenance_fallback(client, db):
-    rec = await _img(db, 1)
-    _, s = await _artist_source(db, "Bob", "bob")
-    post = Post(source_id=s.id, external_post_id="2")
-    db.add(post)
-    await db.flush()
-    db.add(ImageProvenance(image_record_id=rec.id, post_id=post.id,
-                           source_id=s.id))
-    await db.flush()
-    await db.commit()  # rec.primary_post_id stays NULL
-
-    resp = await client.get("/api/gallery/scroll?limit=10")
-    body = await resp.get_json()
-    item = next(i for i in body["images"] if i["id"] == rec.id)
-    assert item["artist"] == {"name": "Bob", "slug": "bob"}
-
-
 @pytest.mark.asyncio
 async def test_scroll_artist_null_when_none(client, db):
     rec = await _img(db, 1)
@@ -92,3 +50,20 @@ async def test_scroll_artist_null_when_none(client, db):
     body = await resp.get_json()
     item = next(i for i in body["images"] if i["id"] == rec.id)
     assert item["artist"] is None
+
+
+@pytest.mark.asyncio
+async def test_scroll_artist_via_artist_id(client, db):
+    # FC-2d-vii-c: the canonical resolution path is image_record.artist_id
+    # (covers folder-style images with no provenance too).
+    rec = await _img(db, 1)
+    a, _ = await _artist_source(db, "Folder", "folder")
+    rec.artist_id = a.id
+    await db.flush()
+    await db.commit()
+
+    resp = await client.get("/api/gallery/scroll?limit=10")
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    item = next(i for i in body["images"] if i["id"] == rec.id)
+    assert item["artist"] == {"name": "Folder", "slug": "folder"}