[magnusp]

Summary

Extracts the xerial 3.53.4.0 column type mapping out of LibsqlResultSetMetaData into a package-private XerialColumnType. Move only: the ordered if-chain, the storage-class helper, className, the storage-class enum, and the single integer(Value) helper (also used by toTableInfo).

• XerialColumnType holds storageClass(Value), jdbcType(Value, String), className(Value), integer(Value), and the StorageClass enum.
• getColumnType, getColumnClassName, and isSigned delegate.
• getColumnType keeps the original evaluation order: getColumnTypeName before runtimeValue.

Nothing else changes. No test, pom, declared-type parsing, AUTOINCREMENT parser, or table resolver touched.

Fixes #203

Verbatim proof (normalized diff, empty)

Moved blocks: old LibsqlResultSetMetaData 188-272 (getColumnType body), 311-325 (className), 366-380 (storageType), 518-528 (integer + SampleType). Compared against the corresponding blocks in XerialColumnType.

Normalization is renames plus visibility only: SampleType -> StorageClass, storageType -> storageClass, and the private modifier dropped because the moved members are package-private by design.

$ F=libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlResultSetMetaData.java
$ NORM='s/SampleType/StorageClass/g; s/storageType/storageClass/g; s/^([[:space:]]*)private /\1/'
$ git show origin/main:$F | sed -n '188,272p;311,325p;366,380p;518,528p' | sed -E "$NORM" > /tmp/probe-old.txt
$ sed -n '13,97p;100,114p;116,130p;132,142p' \
    libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/XerialColumnType.java | sed -E "$NORM" > /tmp/probe-new.txt
$ diff -u /tmp/probe-old.txt /tmp/probe-new.txt && echo NORMALIZED_DIFF_EMPTY
NORMALIZED_DIFF_EMPTY
$ wc -l /tmp/probe-old.txt /tmp/probe-new.txt
 126 /tmp/probe-old.txt
 126 /tmp/probe-new.txt

Branch order, the NULL participation in every storage block before Types.NUMERIC, the declared type name set (UNSIGNED BIG INT, DATETIME included), className returning Object.class for NULL/BLOB, and the narrow isSigned set (NUMERIC, INTEGER, REAL) all move unchanged. integer(null) is still 0.

Probe

Deleted the BOOLEAN arm from the INTEGER branch in XerialColumnType.jdbcType, then ran the declared-type test:

$ ./mvnw -pl libsql-jdbc -am test -Dtest=LibsqlResultSetMetaDataTest -Dsurefire.failIfNoSpecifiedTests=false
[ERROR] Tests run: 36, Failures: 3, Errors: 0, Skipped: 0
[ERROR]   LibsqlResultSetMetaDataTest.usesDeclaredTypesWhenRuntimeValueIsNull:241->assertDeclaredTypes:506
expected: 16
 but was: 2
[ERROR]   LibsqlResultSetMetaDataTest.usesDeclaredTypesForEmptyResultSet:261->assertDeclaredTypes:506
expected: 16
 but was: 2

16 is Types.BOOLEAN, 2 is Types.NUMERIC. Reverted; git status clean apart from the two intended files, and the full lane is green again.

Line counts

File	Before	After
LibsqlResultSetMetaData.java	544	417
XerialColumnType.java	—	143

Gates

Lane	Result
./mvnw -pl libsql-jdbc -am test	392 tests, 0 failures, 0 errors, 0 skipped
./mvnw spotless:apply then ./mvnw spotless:check	BUILD SUCCESS both
./mvnw -pl libsql-conformance -am verify	272 tests, 0 failures, 0 errors, 7 skipped

Baseline on main: 392 JDBC tests and 272 conformance tests (7 skipped). No assertion edited.