v0.35.1: performance, AGPL licensing and documentation overhaul

- Web Server reads static files inline; proxy middleware chain flattened
- About window with license summary and project links; AGPL-3.0-or-later
- Rewritten documentation: feature list, screenshots, performance guide
- Fix false spikes in per-Vhost request-rate charts

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMsgSXoK4Bph2vU6fSBkAH

src/cache/cache_regression_tests.rs

@@ -6,8 +6,7 @@ mod tests {
         h.insert("cache-control", value.parse().unwrap());
         h
     }
-    // Legacy-policy regression tests explicitly opt out of the new 0.34.7
-    // default; varnish-compatible behavior has its own test module.
+    // Legacy policy; varnish-compatible behavior is tested separately.
     fn settings() -> Settings {
         Settings {
             enabled: true,