Add MyBatis mapper XML support

[15290391025]

Summary

• index MyBatis *Mapper.xml files and extract <select|insert|update|delete id="..."> statements as Java method-like nodes
• emit Java mapper interface references that resolve to namespace.id XML statements
• allow multi-part qualified references through the resolver pre-filter

Validation

• npx tsc --noEmit
• npm run build
• npx vitest run __tests__/extraction.test.ts __tests__/resolution.test.ts --testNamePattern "MyBatis|mapper interface methods"

Note

Full __tests__/extraction.test.ts OOMs in my local Windows/Vitest worker after many existing grammar-heavy tests; the focused MyBatis tests and build pass.