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

src/proxy/forward/success_prepare.rs

@@ -137,8 +137,8 @@ let origin_reason = (cache_ticket.is_some() && origin_plan.is_none()).then(|| {
 let origin_no_transform = crate::transform::no_transform(response.headers());
 let skip_compression = crate::compression::no_transform(response.headers());
 let origin_validators = crate::transform::OriginValidators {
-    etag: response.headers().get("etag").cloned(),
-    last_modified: response.headers().get("last-modified").cloned(),
+    etag: response.headers().get(::http::header::ETAG).cloned(),
+    last_modified: response.headers().get(::http::header::LAST_MODIFIED).cloned(),
 };
 let (mut parts, body) = response.into_parts();
 parts.extensions.insert(origin_validators);
@@ -147,8 +147,8 @@ if skip_compression || range_requested {
 }
 headers::strip_hop_by_hop(&mut parts.headers);
 if websocket_legacy_support && handshake.is_some() {
-    parts.headers.remove("content-length");
-    parts.headers.remove("transfer-encoding");
+    parts.headers.remove(::http::header::CONTENT_LENGTH);
+    parts.headers.remove(::http::header::TRANSFER_ENCODING);
 }
 apply_response_rules(
     &mut parts.headers,
@@ -161,7 +161,7 @@ if let Some(pool) = &route.pool {
     pool.strip_affinity_response(&mut parts.headers);
 }
 if let Some(cookie) = active_affinity_cookie {
-    parts.headers.append("set-cookie", cookie);
+    parts.headers.append(::http::header::SET_COOKIE, cookie);
 }
 let h3_tunnel = handshake.as_ref().is_some_and(|handshake| handshake.h3())
     && upgraded.is_some();
@@ -208,9 +208,9 @@ let mut response = if h3_tunnel {
     };
     exchange.websocket_phase("tunnel_ready");
     parts.status = StatusCode::OK;
-    parts.headers.remove("sec-websocket-accept");
-    parts.headers.remove("content-length");
-    parts.headers.remove("transfer-encoding");
+    parts.headers.remove(::http::header::SEC_WEBSOCKET_ACCEPT);
+    parts.headers.remove(::http::header::CONTENT_LENGTH);
+    parts.headers.remove(::http::header::TRANSFER_ENCODING);
     parts.extensions.insert(crate::compression::Skip);
     parts
         .extensions
@@ -301,8 +301,8 @@ let mut response = if h3_tunnel {
             "RustProxy: HTTP/2 WebSocket tunnel state unavailable\n",
         );
     };
-    parts.headers.remove("content-length");
-    parts.headers.remove("transfer-encoding");
+    parts.headers.remove(::http::header::CONTENT_LENGTH);
+    parts.headers.remove(::http::header::TRANSFER_ENCODING);
     parts.extensions.insert(crate::compression::Skip);
     Response::from_parts(
         parts,
@@ -314,10 +314,10 @@ let mut response = if h3_tunnel {
     {
         parts
             .headers
-            .insert("connection", HeaderValue::from_static("Upgrade"));
+            .insert(::http::header::CONNECTION, HeaderValue::from_static("Upgrade"));
         parts
             .headers
-            .insert("upgrade", HeaderValue::from_static("websocket"));
+            .insert(::http::header::UPGRADE, HeaderValue::from_static("websocket"));
         websocket::spawn(
             state.clone(),
             downstream,
@@ -342,8 +342,7 @@ if intercept_origin_error {
         Some(route),
         admin_control_plane,
     );
-    response.headers_mut().insert(
-        "cache-control",
+    response.headers_mut().insert(::http::header::CACHE_CONTROL,
         HeaderValue::from_static("no-store"),
     );
 }