[magnusp]

What changed

Moved the generated-key state out of LibsqlStatement into a package-private GeneratedKeys. The statement keeps its three entry points (updateGeneratedKeys, clearGeneratedKeys, and getGeneratedKeys) and its stateLock. GeneratedKeys owns the insert detection, the single and batch result shaping, and the close-on-clear rule.

The batch call now runs directly under the stateLock that executeBatch already holds, so the private wrapper disappeared.

Behavior preserved

The generated-key column labels stay last_insert_rowid() and 1. Single and batch keys keep their order and values. A non-insert step contributes no key. Every exception type and message is unchanged. The public and protected statement methods are unchanged. The public API is unchanged.

Pins added

Test	Behavior pinned
emptyGeneratedKeysUseTheXerialColumnName	A statement without keys reports the empty result with column name 1.
mixedBatchReportsOnlyTheInsertStepKeys	A batch with an insert then an update reports only the insert rowid.

Mutant kills

Probe	Result
Rename the empty-key column from 1 to 0.	1 pin failed. Reverted.
Accept every batch rowid instead of only insert steps.	1 pin failed. Reverted.

Diff (file statistics)

 GeneratedKeys.java               | 114 +++++++++++++++++++++
 LibsqlStatement.java             |  99 +-----------------
 LibsqlGeneratedKeysTest.java     |  28 +++++
 3 files changed, 147 insertions(+), 94 deletions(-)

Line counts

File	Before	After
LibsqlStatement.java	703	614
GeneratedKeys.java	0	114

Probe

The first probe renamed the empty generated-key column, and the column-name pin failed. The second probe removed the insert-only filter from the batch path, and the mixed-batch pin failed. Both probes were reverted before the final lane run.

Lanes

Command	Result
mise exec -- ./mvnw -pl libsql-jdbc -am test	Pass, 1559 tests (baseline 1557 plus 2 pins).
mise exec -- ./mvnw spotless:check	Pass.
mise exec -- ./mvnw -pl libsql-conformance -am verify	Pass, 271 tests, 6 skipped.
DOCKER_CONFIG=... mise exec -- ./mvnw -pl libsql-itests -am verify	Pass, 43 driver ITs and 192 itests. The first attempt hit a RootlessKit port collision for Toxiproxy; the retry passed.

• My code follows the code style of this project (./mvnw spotless:check).
• I have added tests that prove my fix is effective or that my feature works.
• All new and existing tests passed (./mvnw clean verify).
• I have updated documentation where appropriate.

Closes #280