feat(phash): import task maps 'superseded' to complete + re-queues ML/thumbnail

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

tests/test_phash_dedup.py

@@ -136,3 +136,21 @@ def test_threshold_controls_match(importer, import_layout):
     _write(b, (104, 100, 100), (900, 900))  # tiny tweak
     r = importer.import_one(b)
     assert r.status == "imported"  # threshold 0 → not treated as near-dup
+
+
+def test_import_task_maps_superseded_to_complete_and_requeues():
+    from backend.app.services.importer import ImportResult
+    from backend.app.tasks.import_file import _map_result_to_status
+
+    assert _map_result_to_status(
+        ImportResult(status="superseded", image_id=5)
+    ) == ("complete", True)
+    assert _map_result_to_status(
+        ImportResult(status="imported", image_id=5)
+    ) == ("complete", True)
+    assert _map_result_to_status(
+        ImportResult(status="skipped", skip_reason=SkipReason.duplicate_phash)
+    ) == ("skipped", False)
+    assert _map_result_to_status(
+        ImportResult(status="failed", error="boom")
+    ) == ("failed", False)