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/cache/model/entry.rs

@@ -333,8 +333,7 @@ impl Settings {
             if transformed {
                 value.push_str("; transformed");
             }
-            headers.append(
-                "cache-status",
+            headers.append(::http::header::CACHE_STATUS,
                 HeaderValue::from_str(&value).expect("generated Cache-Status member"),
             );
         }

src/cache/model/maintenance.rs

@@ -68,6 +68,7 @@ pub struct Cache {
     cold_read_bytes_active: AtomicU64,
     revalidating: Mutex<HashSet<Key>>,
     fill_flights: Mutex<HashMap<Key, Arc<FillFlight>>>,
+    uncacheable_until: Mutex<HashMap<Key, std::time::Instant>>,
     fill_flight_sequence: AtomicU64,
     collapse_waiters: AtomicU64,
     bans: Mutex<Vec<BanRule>>,
@@ -183,35 +184,35 @@ impl Revalidation {
         &self.headers
     }
     pub fn apply_validators(&self, headers: &mut HeaderMap) -> bool {
-        if headers.contains_key("if-none-match") {
-            let Some(public_etag) = self.headers.get("etag").and_then(|v| v.to_str().ok()) else {
+        if headers.contains_key(::http::header::IF_NONE_MATCH) {
+            let Some(public_etag) = self.headers.get(::http::header::ETAG).and_then(|v| v.to_str().ok()) else {
                 return false;
             };
             if !single_if_none_match_matches(headers, public_etag) {
                 return false;
             }
             if let Some(origin) = self.origin_etag.clone() {
-                headers.insert("if-none-match", origin);
-                headers.remove("if-modified-since");
+                headers.insert(::http::header::IF_NONE_MATCH, origin);
+                headers.remove(::http::header::IF_MODIFIED_SINCE);
                 return true;
             }
             if let Some(modified) = self.origin_last_modified.clone() {
-                headers.remove("if-none-match");
-                headers.insert("if-modified-since", modified);
+                headers.remove(::http::header::IF_NONE_MATCH);
+                headers.insert(::http::header::IF_MODIFIED_SINCE, modified);
                 return true;
             }
             return false;
         }
-        if headers.contains_key("if-modified-since") {
+        if headers.contains_key(::http::header::IF_MODIFIED_SINCE) {
             let Some(cached) = self
                 .headers
-                .get("last-modified")
+                .get(::http::header::LAST_MODIFIED)
                 .and_then(|v| v.to_str().ok())
             else {
                 return false;
             };
             let Some(client) = headers
-                .get("if-modified-since")
+                .get(::http::header::IF_MODIFIED_SINCE)
                 .and_then(|v| v.to_str().ok())
             else {
                 return false;
@@ -226,16 +227,16 @@ impl Revalidation {
             let Some(origin) = self.origin_last_modified.clone() else {
                 return false;
             };
-            headers.insert("if-modified-since", origin);
+            headers.insert(::http::header::IF_MODIFIED_SINCE, origin);
             return true;
         }
         if let Some(etag) = self.origin_etag.clone() {
-            headers.insert("if-none-match", etag);
-            headers.remove("if-modified-since");
+            headers.insert(::http::header::IF_NONE_MATCH, etag);
+            headers.remove(::http::header::IF_MODIFIED_SINCE);
             true
         } else if let Some(modified) = self.origin_last_modified.clone() {
-            headers.insert("if-modified-since", modified);
-            headers.remove("if-none-match");
+            headers.insert(::http::header::IF_MODIFIED_SINCE, modified);
+            headers.remove(::http::header::IF_NONE_MATCH);
             true
         } else {
             false
@@ -281,7 +282,7 @@ impl Revalidation {
     }
     pub fn merge_validation_headers(&self, validation: &HeaderMap) -> HeaderMap {
         let mut merged = merge_revalidated_headers(&self.headers, validation);
-        let public_etag = self.headers.get("etag").cloned();
+        let public_etag = self.headers.get(::http::header::ETAG).cloned();
         let representation_etag_differs = public_etag.as_ref().is_some_and(|public| {
             self.origin_etag
                 .as_ref()
@@ -289,7 +290,7 @@ impl Revalidation {
         });
         if representation_etag_differs {
             if let Some(public) = public_etag {
-                merged.insert("etag", public);
+                merged.insert(::http::header::ETAG, public);
             }
         }
         merged
@@ -316,7 +317,7 @@ impl Revalidation {
 }
 fn vary_names(headers: &HeaderMap) -> Option<Vec<String>> {
     let mut names = Vec::new();
-    for value in headers.get_all("vary") {
+    for value in headers.get_all(::http::header::VARY) {
         for raw in value.to_str().ok()?.split(',') {
             let raw = raw.trim();
             if raw.is_empty() || raw == "*" {

src/cache/model/views.rs

@@ -77,7 +77,7 @@ fn retention_deadline(
 }
 
 fn has_validator(headers: &HeaderMap) -> bool {
-    headers.contains_key("etag") || headers.contains_key("last-modified")
+    headers.contains_key(::http::header::ETAG) || headers.contains_key(::http::header::LAST_MODIFIED)
 }
 
 fn stale_forbidden(must_revalidate: bool, proxy_revalidate: bool) -> bool {