[magnusp]

Fixes #214

Collapses the five duplicated send/error-mapping blocks in LibsqlConnection into one send core plus two named wrappers, and removes the second update-count loop. The autoCommit dispatch stays in executeStatement and executeBatchResults.

What changed

• Added sendOnStream(Stmt) and sendBatchOnStream(Batch), both delegating to one generic sending(Supplier) that owns the LibsqlException → SQLException mapping.
• executeBatch(List) is now one line over steppedUpdateCounts(executeBatchResults(...)).
• Deleted executeTransactionStatement; its four savepoint call sites now call sendOnStream.
• beginTransaction, endTransaction, and the one-shot branches route through the same helpers.

Preserved

• Failed BEGIN closes the fresh stream and leaves the begin pending.
• Failed COMMIT/ROLLBACK leaves the stream open.
• Empty batch returns an empty list and sends no request.
• stateLock still held by every caller.
• No message, request-order, or behavior change; no test files touched; pom.xml untouched.

Diff

 libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlConnection.java | 111 +++++++++------------
 1 file changed, 48 insertions(+), 63 deletions(-)

LibsqlConnection.java: 763 → 748 lines (under the 750-line budget).

Probe

Removed the closeStreamQuietly() on a failed BEGIN:

[ERROR] Tests run: 36, Failures: 1, Errors: 1, Skipped: 0
[ERROR]   LibsqlConnectionTest.aFailedBeginLeavesTheBeginPendingAndNoStatementRuns:200
Expected size: 2 but was: 1
[ERROR]   LibsqlConnectionTest.aFailedBeginPinsTheLazyBeginStateUntilTheRetrySucceeds:234

Reverted; LibsqlConnectionTest green again.

Verification

Lane	Result
./mvnw -pl libsql-jdbc -am test	396 JDBC tests (431 with codec), 0 failures
./mvnw spotless:check	clean
./mvnw -pl libsql-conformance -am verify	272 tests, 0 failures, 7 skipped
DOCKER_CONFIG=... ./mvnw -pl libsql-itests -am verify	43 tests, 0 failures