Fix tsconfig node_modules glob

[liurenfeng94-ops]

Fixes a hidden-character bug in tsconfig discovery.

getTsconfigFile was excluding node_modules with a glob that accidentally contained a zero-width character, so the exclusion could silently fail. This change moves the glob strings into a tiny shared helper and makes the node_modules exclusion explicit again.

The helper also gives us a small place to lock the glob values down in tests.

Validation:

• pnpm vitest run test/tsconfig-search.test.ts
• pnpm vitest run
• pnpm typecheck
• pnpm exec eslint .
• pnpm build

[github-actions]

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[liurenfeng94-ops]

Thanks — I rewrote the description in my own words. The change is just the glob cleanup plus a tiny helper/test so the exclusion stays explicit and covered.