feat(sql): index Dysflow saved Access queries (queries/*.sql)

[ardelperal]

Slice 2 of 2 (chained on #14). Closes the other high-value VBA-for-Access gap: the saved-query/data layer.

What

Dysflow exports saved Access QueryDefs as queries/.sql + a queries.json manifest. CodeGraph did not recognize .sql at all, so the data layer was invisible and VBA-vs-table usage couldn't be traced.

Changes

• New SqlQueryExtractor: a 'query' node per .sql + 'references' edges to tables it names (FROM/JOIN/INTO/UPDATE; bracketed names like [Order Details] unwrapped; deduped), tagged synthesizedBy 'sql-query-table'.
• New Language 'sql' + NodeKind 'query'; routed in the tree-sitter dispatch.
• Detection gated on a sibling queries.json (per decision) so non-Access repos are untouched: .sql stays out of EXTENSION_MAP (isSourceFile stays false), and every discovery path admits a .sql only when its dir carries the manifest — the git-ls-files scan, the non-git fs walk, the incremental git-status sync, and the file watcher.

Tests (strict TDD)

• extraction-sql-query.test.ts — extractor output shape (9 cases), red then green.
• sql-query-discovery-gate.test.ts — E2E: a .sql with sibling queries.json is indexed; one without is ignored (proves zero collateral for non-Access repos).
• Real-fixtures E2E extended with src/queries/ (Dysflow layout) — exercises the git-ls-files path.
• Full suite: only the pre-existing Windows-flaky failures (frameworks-integration JVM, mcp-roots EPERM) remain, identical to baseline. tsc clean.

Note

Chained on #14 (feat/vba-enums-consts). Merge #14 first; GitHub will auto-retarget this PR to main.