Pages under docs/api/ return 404 on direct load due to SPA fallback collision with /api routes

[yumike]

Summary

Any markdown page whose URL starts with /api/ (e.g. docs/api/usage.md → /api/usage) returns 404 when loaded directly or refreshed in the browser.

Reproduction

1. Create docs/api/usage.md in an rw serve project.
2. Navigate to the page via the sidebar — it loads (SPA client-side routing, no server hit).
3. Refresh the browser, or paste http://localhost:7979/api/usage into a new tab.
4. Server returns 404 Not Found.

Root cause

crates/rw-server/src/static_files.rs:37 excludes any path starting with api/ from the SPA fallback:

let is_spa_route = !path.starts_with("api/") && !path.contains('.');

The intent was to avoid serving index.html for unmatched API calls, but the check is too broad — it also blocks legitimate doc pages under /api/*.

Request flow for /api/usage:

1. Router does not match /api/config, /api/navigation, /api/pages/..., or /api/comments.
2. Falls through to static_files::serve_asset.
3. path.starts_with("api/") is true → is_spa_route = false → 404.

Suggested fixes

Two options:

1. Tighten the fallback check — only skip SPA fallback for the actual API prefixes (api/config, api/navigation, api/pages/, api/comments). Smallest change; keeps the /api/* URL contract.
2. Move API under a reserved prefix — e.g. /_api/* or /__rw/api/*. Eliminates the collision entirely but changes the public API surface (frontend client, tests, any external callers of /api/comments).

Option 1 is lower-risk; option 2 is cleaner long-term.

Related code

• crates/rw-server/src/app.rs:22-35 — route registrations
• crates/rw-server/src/static_files.rs:37 — fallback check