fix(education): lock collection migration adoption

yudao-module-education/src/main/resources/db/migration/education/V4110__add_manual_question_collection.sql

@@ -1,6 +1,13 @@
 -- EDU-010: current-tenant manual Question Collection authoring lifecycle.
 -- JAVA_READ application authority is enforced in Java; database guards protect direct mutation.
 
+-- Prevent concurrent collection/membership/question mutation across adoption validation,
+-- backfill, and trigger installation while retaining ordinary reads.
+LOCK TABLE education_question_collection,
+           education_question_collection_question,
+           education_question
+    IN SHARE ROW EXCLUSIVE MODE;
+
 ALTER TABLE education_question_collection
     ADD COLUMN publication_status VARCHAR(16) NOT NULL DEFAULT 'ACTIVE',
     ADD COLUMN authoring_version INTEGER NOT NULL DEFAULT 0,

yudao-module-education/src/test/java/cn/iocoder/yudao/module/education/test/EducationFlywayMigrationIntegrationTest.java

@@ -675,6 +675,33 @@ class EducationFlywayMigrationIntegrationTest {
         }
     }
 
+    @Test
+    void shouldUseMigrationLocksThatBlockMembershipAndQuestionWrites() throws SQLException {
+        String schema = createSchema("collection_lock_modes");
+        configureFlyway(schema, false).target("4100").load().migrate();
+        try (Connection locker = DriverManager.getConnection(jdbcUrl(schema), USER, PASSWORD);
+             Connection writer = DriverManager.getConnection(jdbcUrl(schema), USER, PASSWORD)) {
+            locker.setAutoCommit(false);
+            try (var statement = locker.createStatement()) {
+                statement.execute("LOCK TABLE education_question_collection, education_question_collection_question, education_question IN SHARE ROW EXCLUSIVE MODE");
+            }
+            assertThat(queryLong(schema, """
+                    SELECT count(*) FROM pg_locks lock
+                    JOIN pg_class relation ON relation.oid=lock.relation
+                    WHERE lock.pid<>pg_backend_pid() AND lock.mode='ShareRowExclusiveLock' AND lock.granted
+                      AND relation.relname IN ('education_question_collection','education_question_collection_question','education_question')
+                    """)).isEqualTo(3L);
+            try (var statement = writer.createStatement()) {
+                statement.execute("SET lock_timeout='250ms'");
+                assertThatThrownBy(() -> statement.execute("DELETE FROM education_question_collection_question WHERE false"))
+                        .hasMessageContaining("lock timeout");
+                assertThatThrownBy(() -> statement.execute("UPDATE education_question SET deleted=deleted WHERE false"))
+                        .hasMessageContaining("lock timeout");
+            }
+            locker.rollback();
+        }
+    }
+
     @Test
     void shouldFailV4110ForHistoricalCollectionEntryDivergence() throws SQLException {
         String schema = createSchema("collection_entry_divergence");