chore(deps): force cosmiconfig typescript override to fix dependabot CI (#700)

PR #697 was failing CI because cosmiconfig@9 (via semantic-release@25)
declares an optional typescript peer dependency at >=4.9.5. npm 7+
installs the latest matching version for optional peers regardless of
the top-level pin, so it was choosing typescript@6.0.3 — a nested
install Dependabot's lockfile didn't include, causing 'npm ci' to fail.

- Bump top-level typescript pin: ~4.9.3 -> ~4.9.5 (cosmiconfig's floor)
- Add overrides.cosmiconfig.typescript = ~4.9.5 to prevent the nested
  typescript@6 install
- Fix pre-existing prettier error in src/utils.ts:20 (indexed access
  type now requires parentheses around 'typeof units')

Verified locally: npm ci succeeds, 287/287 tests pass, lint clean,
build clean. Lockfile no longer contains a nested
node_modules/semantic-release/node_modules/typescript entry.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: sid88in