Add executeWithKey() to JPAInsertClause and HibernateInsertClause

[zio0911]

Summary

• Add executeWithKey(Path<T>) and executeWithKey(Class<T>) to JPAInsertClause and HibernateInsertClause
• Bypass JPQL and execute native SQL INSERT via JDBC with Statement.RETURN_GENERATED_KEYS to retrieve auto-generated keys
• Add JpaInsertNativeHelper utility to resolve @Table/@Column annotations and build native SQL INSERT statements
• Add doReturningWork() to SessionHolder interface and all implementations

Closes #1692

Motivation

The SQL module's SQLInsertClause supports executeWithKey(), but the JPA module does not. This forces JPA users to fall back to EntityManager.persist() + flush() for insert + key return, breaking the consistent QueryDSL style.

Using the SQL module in a JPA project requires a separate SQLQueryFactory, SQL-specific Q-classes, and managing two query factories — excessive overhead just for insert key return.

Before / After

Before — must break out of QueryDSL:

entityManager.persist(entity);
entityManager.flush();
Long seq = entity.getSeq();

After — stays in QueryDSL:

Long seq = queryFactory.insert(role)
    .set(role.name, dto.roleName())
    .set(role.status, status)
    .executeWithKey(role.seq);

Implementation

Since JPA's Query.executeUpdate() only returns affected row count, the implementation:

1. Reads @Table / @Column annotations to build native SQL (same pattern as NativeSQLSerializer)
2. HibernateInsertClause uses Session.doReturningWork() for JDBC access
3. JPAInsertClause uses EntityManager.unwrap(Session.class).doReturningWork()

Limitations

• INSERT ... SELECT subqueries are not supported (throws UnsupportedOperationException)
• Requires explicit @Table / @Column annotations if using a custom Hibernate PhysicalNamingStrategy
• JPAInsertClause currently relies on Hibernate as the JPA provider

Test plan

• Unit tests for JpaInsertNativeHelper (table name resolution, column name resolution, SQL generation)
• Integration tests for HibernateInsertClause.executeWithKey() (set style, columns/values style, class type, multiple inserts, column annotation, subquery rejection)
• Integration tests for JPAInsertClause.executeWithKey() (same scenarios)
• All 18 new tests pass
• Existing tests unaffected (./mvnw -Pdev verify passes)
• Code formatted (git-code-format pre-commit hook)

[kamilkrzywanski]

@zio0911 Shouldn't a similar approach to escaping table and column names as in NativeSQLSerializer be used in JpaInsertNativeHelper? See for example: getTemplates().quoteIdentifier(column.name(), precededByDot).