fix(ssg): Fix SSG Extension Map

[pspeter3]

Pass the extension map through the generation methods.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.34%. Comparing base (ebc7e4b) to head (343c0bc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4130   +/-   ##
=======================================
  Coverage   91.34%   91.34%           
=======================================
  Files         168      168           
  Lines       10700    10702    +2     
  Branches     3148     3062   -86     
=======================================
+ Hits         9774     9776    +2     
  Misses        925      925           
  Partials        1        1           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[yusukebe]

LGTM!

[yusukebe]

@pspeter3 Looks good! I'll merge and release a new version soon. Thank you so much!