<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Broaden injection to extensionless and .html routes, gate by
Content-Type, and conditionally strip caching/compression headers only
when injecting.
> 
> - **Proxy HTML injection**:
> - Update `needsInjection(pathname)` to inject for routes without
extensions and `.html` files (e.g., `/`, `/foo`, `/foo/bar`, `*.html`).
> - Only request uncompressed content and remove `if-none-match` when
`needsInjection(target.pathname)` is true.
> - During upstream response, inject only if `Content-Type` includes
`text/html`; otherwise pass through without modification.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
2986ceccea64e7881a2197a2a0b202216f21d27d. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->