fix(m3): Option A must-fix #79 #82 #83 #84 #89 #98

- #79 publish SKU/create via WooClient (User-Agent + typed 403 unrecoverable)
- #82 stale_field current_options from live taxonomy + owner labels
- #83 create allowlist/extra-key safe; taxonomy+enum 4xx on create
- #84 health woo_reachable real probe (non-failing); version 0.5.0-m3
- #89 review persists assembled title/short after taxonomy lock; UI applies
- #98 live-edge from synced term; attrs resolved by slug then name

backend/tests/test_slabs_api.py

@@ -260,3 +260,47 @@ def test_delete_published_conflict(client, db):
     conn.commit()
     resp = client.delete(f"/api/v1/slabs/{slab_id}")
     assert resp.status_code == 409
+
+
+def test_stale_field_returns_live_options_not_submitted_value(client, db):
+    """#82 / PUBLISH-20: current_options is the live taxonomy list, not the bad id."""
+    slab_id = str(uuid.uuid4())
+    payload = {
+        "id": slab_id, "sku": "SKU-STALE", "length_in": 10, "thickness_in": 2, "sqft": 20, "bdft": 5,
+        "width_min_in": 1, "width_max_in": 2, "width_avg_in": 1.5,
+    }
+    assert client.post("/api/v1/slabs", json=payload).status_code == 201
+    resp = client.put(f"/api/v1/slabs/{slab_id}", json={"client_rev": 1, "edge_type_term_id": 999})
+    assert resp.status_code == 422
+    body = resp.json()
+    assert body["error"]["code"] == "stale_field"
+    opts = body["error"]["detail"]["current_options"]
+    assert isinstance(opts, list) and opts
+    assert all("id" in o and "name" in o for o in opts)
+    assert 999 not in [o["id"] for o in opts]
+    assert "Edge type" in body["error"]["message"] or "edge" in body["error"]["message"].lower()
+
+
+def test_create_extra_key_and_bad_taxonomy_are_4xx(client, db):
+    """#83: extra keys and bad taxonomy ids must not 500."""
+    slab_id = str(uuid.uuid4())
+    base = {
+        "id": slab_id, "sku": "SKU-XTRA", "length_in": 10, "thickness_in": 2, "sqft": 20, "bdft": 5,
+        "width_min_in": 1, "width_max_in": 2, "width_avg_in": 1.5,
+        "status": "published",  # server-managed; must be dropped, not bind-break
+    }
+    r = client.post("/api/v1/slabs", json=base)
+    assert r.status_code == 201, r.text
+    assert r.json()["status"] == "calibrated"
+    # Bad taxonomy on create
+    r2 = client.post("/api/v1/slabs", json={
+        **base, "id": str(uuid.uuid4()), "sku": "SKU-BADTAX", "species_id": 999,
+    })
+    assert r2.status_code == 422
+    assert r2.json()["error"]["code"] == "stale_field"
+    # Bad enum
+    r3 = client.post("/api/v1/slabs", json={
+        **base, "id": str(uuid.uuid4()), "sku": "SKU-BADENUM", "price_source": "not-a-source",
+    })
+    assert r3.status_code == 400
+    assert r3.json()["error"]["code"] == "validation"