chore(pre-commit): add local schema generation sync check

[sakinaroufid]

Description

Adds a pre-commit hook that runs node generate_ts_schema_types.js and checks git diff --exit-code -- generated/schema-types.ts to catch schema desync locally before committing, giving instant feedback instead of waiting for CI.

This complements the CI workflow added in part 1 — CI remains as a safety net for contributors who bypass or don't have pre-commit installed.

Depends on part 1 (#230) being merged first, which fixes the generator's source path so the hook produces correct output.

This is part 2 of 3 from #13, split per maintainer request.

Type of change

• New feature (non-breaking change which adds functionality)

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Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes