fix(docs-site): patch elm-pages base path for GitHub Pages

[ryanbas21]

Summary

• Patch elm-pages v3.5.1 codegen to fix urlToRoute not stripping the base path (causing all pages to pre-render as "Page not found")
• Simplify CI workflow — patched build outputs correct structure directly
• Fixes the broken deployment at ryanbas21.github.io/devtools/

This is a follow-up to #29 which configured the base path but hit an elm-pages bug where the pre-renderer couldn't match routes.

What was wrong

elm-pages' --base /devtools/ flag correctly sets baseUrl for link generation, but the generated urlToRoute function passes the full URL path (e.g., /devtools/docs/getting-started) directly to segmentsToRoute without stripping the base prefix first. Every route match fails, so all pages pre-render as "Page not found."

The fix

A pnpm patch on elm-pages@3.5.1 that inlines base-path stripping into the urlToRoute codegen, so the generated function becomes:

urlToRoute url =
    if String.startsWith baseUrl url.path then
        segmentsToRoute (splitPath (String.dropLeft (String.length baseUrl) url.path))
    else
        segmentsToRoute (splitPath url.path)

Test plan

• CI build passes
• Visit ryanbas21.github.io/devtools/ — should show full landing page with styling
• Navigation links resolve correctly (sidebar, header, package cards)
• Client-side SPA routing works (clicking links doesn't full-page reload)
• Direct URL access works (e.g., /devtools/docs/getting-started)

🤖 Generated with Claude Code