[codex] parse tsconfig JSONC without stripping globs

[chaochaoweb3]

Summary

• replace the naive tsconfig JSONC comment stripping with a string-aware scanner
• preserve comment-looking tokens inside string literals such as **/*.ts
• add a regression test that keeps path aliases when include globs and block comments are both present

Fixes #502

Validation

• npm exec --yes --package=pnpm@10.6.2 -- pnpm install --frozen-lockfile
• npm exec --yes --package=pnpm@10.6.2 -- pnpm vitest run understand-anything-plugin/src/tests/extract-import-map.test.mjs
• npm exec --yes --package=pnpm@10.6.2 -- pnpm eslint understand-anything-plugin/skills/understand/extract-import-map.mjs understand-anything-plugin/src/tests/extract-import-map.test.mjs
• node --check understand-anything-plugin/skills/understand/extract-import-map.mjs
• git diff --check