test(db): verify V42 partial unique index for QUEUED training runs per person

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/test/java/org/raddatz/familienarchiv/repository/MigrationIntegrationTest.java

@@ -217,8 +217,71 @@ class MigrationIntegrationTest {
         assertThat(stored).isEqualTo("sage");
     }
 
+    // ─── V42: idx_training_runs_queued_per_person partial unique index ────────
+
+    @Test
+    @Transactional(propagation = Propagation.NOT_SUPPORTED)
+    void v42_partialUniqueIndex_preventsTwoQueuedRunsForSamePerson() {
+        UUID personId = createPerson("V42Test", "SamePerson");
+        jdbc.update("""
+                INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                VALUES (gen_random_uuid(), 'QUEUED', 10, 2, 'sender_x', ?)
+                """, personId);
+
+        assertThatThrownBy(() ->
+                jdbc.update("""
+                        INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                        VALUES (gen_random_uuid(), 'QUEUED', 5, 1, 'sender_x', ?)
+                        """, personId)
+        ).isInstanceOf(DataIntegrityViolationException.class);
+
+        jdbc.update("DELETE FROM ocr_training_runs WHERE person_id = ?", personId);
+        jdbc.update("DELETE FROM persons WHERE id = ?", personId);
+    }
+
+    @Test
+    void v42_partialUniqueIndex_allowsQueuedRunsForDifferentPersons() {
+        UUID person1 = createPerson("V42Test", "PersonA");
+        UUID person2 = createPerson("V42Test", "PersonB");
+
+        int rows1 = jdbc.update("""
+                INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                VALUES (gen_random_uuid(), 'QUEUED', 10, 2, 'sender_a', ?)
+                """, person1);
+        int rows2 = jdbc.update("""
+                INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                VALUES (gen_random_uuid(), 'QUEUED', 5, 1, 'sender_b', ?)
+                """, person2);
+
+        assertThat(rows1).isEqualTo(1);
+        assertThat(rows2).isEqualTo(1);
+    }
+
+    @Test
+    void v42_partialUniqueIndex_allowsMultipleDoneRunsForSamePerson() {
+        UUID personId = createPerson("V42Test", "DonePerson");
+
+        int rows1 = jdbc.update("""
+                INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                VALUES (gen_random_uuid(), 'DONE', 10, 2, 'sender_x', ?)
+                """, personId);
+        int rows2 = jdbc.update("""
+                INSERT INTO ocr_training_runs (id, status, block_count, document_count, model_name, person_id)
+                VALUES (gen_random_uuid(), 'DONE', 15, 3, 'sender_x', ?)
+                """, personId);
+
+        assertThat(rows1).isEqualTo(1);
+        assertThat(rows2).isEqualTo(1);
+    }
+
     // ─── helpers ─────────────────────────────────────────────────────────────
 
+    private UUID createPerson(String firstName, String lastName) {
+        UUID id = UUID.randomUUID();
+        jdbc.update("INSERT INTO persons (id, first_name, last_name) VALUES (?, ?, ?)", id, firstName, lastName);
+        return id;
+    }
+
     private UUID createTag(String name) {
         UUID id = UUID.randomUUID();
         jdbc.update("INSERT INTO tag (id, name) VALUES (?, ?)", id, name);