feat(trail): slash support

[MadebyAe]

Fix: Generate index.html for routes with trailing slashes

Problem
Routes ending with a trailing slash (e.g. /about/, /work/project/) currently generate invalid paths like dist/about/.html instead of dist/about/index.html, breaking standard web server behavior.

Root Cause
getValidatedFileName.js always appends .html to routes without extensions, ignoring trailing slashes.

Solution
Update logic to detect trailing slashes and append index.html instead of .html:

return fileName.endsWith('/')
  ? `${fileName}index.html`
  : `${fileName}.html`;

Examples

Route	Before	After
/about/	dist/about/.html ❌	dist/about/index.html ✅
/work/project/	dist/work/project/.html ❌	dist/work/project/index.html ✅

Backward Compatibility

• /page → /page.html (unchanged)
• / → /index.html (unchanged)
• /page.html → /page.html (unchanged)