[magnusp]

Fixes #100

Contract: Hrana 3 is the source of truth for transport, values, and metadata. java.sql is the source of truth for the JDBC surface. xerial/sqlite-jdbc is a behavioral reference and conformance foundation, never a copy target.

Protocol basis

StmtResult.cols is authoritative for column count, name, and decltype. The protocol has no column-origin field, so the local parser supplies only table origin and nullability. The parser expansion is now compared with cols.size(), and it never overrides the protocol width.

Change

• resolveColumnOrigins passes cols.size() to a new SqlTableReference.resolve(sql, schema, columnCount) overload that discards the resolution when the parser expansion count differs. Every misalignment reports an empty table name and columnNullableUnknown instead of a wrong table.
• Table column lists load through pragma_table_xinfo with p.hidden != 1, so generated columns are present in * expansions and virtual-table hidden columns stay out.
• * expansion drops the right-side duplicate of a USING or NATURAL join column, which is what SQLite does.
• Tests cover a USING join, a NATURAL join, a generated-column table joined with another table, a VALUES subquery, and an unknown source, each asserting the resolved column count equals the result column count.

Evidence

Red at base 2c83a84 (new tests only, width seam returning the parser result unchanged):

• SqlTableReferenceTest: 22 run, 3 failed. USING, NATURAL, and width-discard cases failed on [resolved column count equals the result column count] Expecting value to be true but was false. Log: /tmp/xerial-parity-i100/red-parser.log.
• LibsqlResultSetMetaDataTest: 30 run, 3 failed. resolvesUsingJoinStarColumnsToTheLeftTable expected "c" but was "b", resolvesGeneratedColumnStarColumnsThroughTableXinfo expected "g" but was "c", leavesEveryColumnUnknownWhenTheStarWidthDiffers Expecting empty but was: "c". Log: /tmp/xerial-parity-i100/red-metadata.log.

Green at head a755f21:

Lane	Command	Result
1 Regression	./mvnw -pl libsql-jdbc test -Dtest=SqlTableReferenceTest	22 run, 0 failed (/tmp/xerial-parity-i100/green-parser.log)
2 Metadata	./mvnw -pl libsql-jdbc test -Dtest=LibsqlResultSetMetaDataTest	30 run, 0 failed (/tmp/xerial-parity-i100/green-metadata.log)
3 USING end to end	resolvesUsingJoinStarColumnsToTheLeftTable	merged column resolves to the left table a, z to c
4 Module suite	./mvnw -pl libsql-jdbc test	197 run, 0 failed, BUILD SUCCESS (lane-4-module-suite.log)
5 Conformance	./mvnw -pl libsql-conformance -am verify	115 run, 0 failed, 1 skipped, BUILD SUCCESS (lane-5-conformance.log)
6 xerial control	./mvnw -pl libsql-conformance -am -Pxerial-control verify	100 run, 0 failed, 1 skipped, BUILD SUCCESS (lane-6-control.log)
7 Format	./mvnw spotless:check	BUILD SUCCESS, no violations (lane-7-spotless.log)
8 Reactor	./mvnw test	BUILD SUCCESS, 197 run in libsql-jdbc (lane-8-reactor.log)
9 Vendored RSMetaDataTest	inside lane 5	13 run, 0 failed
10 Package	./mvnw -pl libsql-jdbc -am package -DskipTests	jar built (lane-10-package.log)

Perf: wall clock of ./mvnw -pl libsql-jdbc test, three interleaved runs per side. Trunk median 2.14 s, head median 2.17 s, +1.4 percent, inside the ten percent rule (perf-interleaved.log).

Divergence

None from SQLite or xerial. When the parser cannot prove alignment the driver reports the documented JDBC unknown values, which is the behavior the issue asks for.

Base 2c83a84, head a755f21.