fix: update eslint glob pattern to include all files correctly

[kyle-seongwoo-jun]

:recycle: Current Situation

• npm lint uses src/**.ts, missing files in subdirectories.

:bulb: Proposed Solution

• Change glob pattern to src/**/*.ts to include all subdirectories.

:gear: Release Notes

• Improved linting coverage for TypeScript files across all subdirectories.

:heavy_plus_sign: Additional Information

Testing

• Added tests to ensure all .ts files are now correctly linted.

Reviewer Nudging

• Review changes in package.json and the new linting test cases.

[kyle-seongwoo-jun]

@donavanbecker sorry for ping, could you check this pr? thank you!

[bwp91]

thanks!