FX-1: auto-map re-run must not PK-collide with confirmed ghosts

_refresh_ai_rows deleted only unconfirmed AI rows, then bulk-inserted freshly
generated rows keyed by a deterministic uuid5 of (template_id, semantic key).
A confirmed ghost keeps that id, so a re-run re-emitted it → primary-key
conflict that failed the whole insert batch (reachable: auto-map is blocked only
when marks exist, not when ghosts are confirmed).

Fix: after the delete, read the ids that survived (confirmed-AI + manual) and
skip re-inserting any freshly generated row whose id matches — preserving the
teacher's curated row and making the insert PK-safe.

Adds test_auto_map_rerun_after_confirm_does_not_pk_collide, which confirms a
ghost at its REAL generated id (the prior test used an arbitrary id that never
collided) and asserts the row survives exactly once with confirmed=True.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

tests/test_exam_templates.py

@@ -674,6 +674,27 @@ def test_auto_map_preserves_manual_and_confirmed_rows_on_rerun(monkeypatch):
     assert "old-ai" not in ids
 
 
+def test_auto_map_rerun_after_confirm_does_not_pk_collide(monkeypatch):
+    # Regression: a confirmed ghost keeps its DETERMINISTIC uuid5 id, which auto-map re-emits on a
+    # re-run — the old code re-inserted that id and PK-collided. Use the real generated id (not an
+    # arbitrary one, unlike the test above) so the collision path is actually exercised.
+    store = _template_with_source()
+    store.update({"exam_questions": [], "exam_response_areas": [], "exam_boundaries": [], "exam_template_layout": []})
+    client, store = make_client(store=store)
+    _patch_auto_map(monkeypatch, store, fast=True)
+    assert client.post("/api/exam/templates/t1/auto-map").status_code == 200
+    ghost_id = next(q["id"] for q in store["exam_questions"] if q["source"] == "ai")
+    # teacher confirms that ghost (row kept, deterministic id unchanged)
+    for q in store["exam_questions"]:
+        if q["id"] == ghost_id:
+            q["confirmed"] = True
+    # re-run auto-map: must not re-insert the same id, and must preserve the teacher's confirmation
+    assert client.post("/api/exam/templates/t1/auto-map").status_code == 200
+    same = [r for r in store["exam_questions"] if r["id"] == ghost_id]
+    assert len(same) == 1, "confirmed ghost must not be duplicated (PK collision) on re-run"
+    assert same[0]["confirmed"] is True, "teacher's confirmation must survive a re-run"
+
+
 def test_auto_map_non_owner_is_403_before_download(monkeypatch):
     store = _template_with_source(owner=OTHER_TEACHER)
     client, store = make_client(user_id=TEACHER, institute_ids=(INST_A,), store=store)