perf: round 11 — StoragePath joined-only, classifier fusion, memoized bodies, query-shape pack, SPA fine-grained stars

Backend (each change benchmark-gated with BEFORE replicas + equivalence
gates; see examples/bench_round11_micro.rs, bench_round11_queries.rs,
bench_log_writer.rs and benches/ROUND11.md — final numbers land in the
follow-up doc commit):

- StoragePath re-representation: single canonical joined String, segments
  derived on demand; File/Folder drop the duplicated path_string field
  (4000→1000 allocs per 500-row listing page)
- Display classifier fusion: classify_display shares one stack-lowered
  extension across the three decision trees; call sites in FileDto,
  folder/favorites/recent handlers, trash, path-resolver (+ interning
  where Arc::from was still used)
- /status.php and /openapi.json memoized into OnceLock<Bytes> (openapi
  rebuilt a 171 KiB spec per request: 2.8 ms → 18 ns)
- NC upload-session PROPFIND: write! + pre-sized body + stack RFC2822
  dates (2.3-2.6x, 2582→772 allocs at 256 chunks)
- REST download: dead FileDto clone removed (capture mime/size + move)
- CalendarEventDto/TrashedItem into_parts moves (11 KiB ical_data memcpy
  gone per CalDAV row); CardDAV getlastmodified stack render
- 4xx path: borrowed ErrorResponse serialize, ErrorKind::as_str,
  not_found/already_exists clone kill
- vCard emit via write!; search page moved out with into_iter skip/take;
  content-hit UUIDs parsed once; group last-user check via HashSet
- RateLimiter: lock-free get + insert (and_upsert_with variant REJECTED
  by benchmark); CSRF token borrow-compare + borrowed cookie extraction
- Thumbnail/preview ETags built from as_str (Debug-identical bytes)
- Encrypted backend: encrypt_in_place_detached single-buffer write path,
  chunk-sized reserve in collect_stream; retry labels made lazy
- PG: deferred upload registration 3→1 round-trips (persist_file CTE
  template); direct_grant_cache for Calendar/AddressBook/Playlist authz
  (single-flight + set_role/clear_role invalidation); expand_user
  tokio::join!; geo clusters min(uuid)::text; recluster face assignment
  batched into one UNNEST update
- People recluster cosine: norms precomputed once (bit-identical gate)
- NC capabilities poll logs demoted to debug; tracing-appender dep added
  for the log-writer benchmark

Frontend:
- ResourceList.selectedEntries O(N)-per-toggle → id-index projection
  O(k log k); favorites/recent consume the batchToolbar snippet param and
  drop their duplicate filter + dead selectedIds mirror
- Recent: star state via new favoriteIds prop — a star click no longer
  rebuilds all N entries
- admin timeAgo >30d fallback uses the cached Intl.DateTimeFormat
- vitest gates in src/lib/components/round11.bench.test.ts

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ABhTEHuGujvwoodh67Kga7

src/interfaces/nextcloud/uploads_handler.rs

@@ -171,53 +171,71 @@ async fn handle_propfind_session(
     // `handle_assemble`'s destination-URL parsing. Storage-side keying
     // stays on `user.username` — upload sessions are per-user, not
     // per-drive.
-    let session_href = format!(
-        "/remote.php/dav/uploads/{}/{}/",
-        session.raw_username, upload_id
-    );
-    let session_last_modified =
-        chrono::DateTime::<chrono::Utc>::from_timestamp(listing.session_mtime as i64, 0)
-            .unwrap_or_else(chrono::Utc::now)
-            .to_rfc2822();
+    // `write!` formats every element straight into a pre-sized `body`; the
+    // old `push_str(&format!(…))` chain allocated a throwaway String per
+    // element per chunk plus growth reallocations from `String::new()`, and
+    // ran the chrono format interpreter per chunk (benches/ROUND11.md §4:
+    // 2.3-2.6x, allocs 2582 → 772 on a 256-chunk session).
+    use std::fmt::Write as _;
 
-    let mut body = String::new();
+    /// `<d:getlastmodified>` via the stack renderer; chrono fallback for
+    /// out-of-range timestamps (same shape as `nextcloud/webdav_handler`).
+    /// RFC 2822 output contains no XML-special characters by construction.
+    fn write_lastmodified(body: &mut String, secs: i64) {
+        let mut buf = [0u8; 31];
+        match crate::common::fmt::rfc2822_utc(&mut buf, secs) {
+            Some(s) => {
+                let _ = write!(body, "<d:getlastmodified>{}</d:getlastmodified>", s);
+            }
+            None => {
+                let dt = chrono::DateTime::<chrono::Utc>::from_timestamp(secs, 0)
+                    .unwrap_or_else(chrono::Utc::now)
+                    .to_rfc2822();
+                let _ = write!(
+                    body,
+                    "<d:getlastmodified>{}</d:getlastmodified>",
+                    xml_escape(&dt)
+                );
+            }
+        }
+    }
+
+    let mut body = String::with_capacity(256 + listing.chunks.len() * 256);
     body.push_str(r#"<?xml version="1.0" encoding="utf-8"?>"#);
     body.push_str(r#"<d:multistatus xmlns:d="DAV:">"#);
 
     // Session collection itself.
     body.push_str("<d:response>");
-    body.push_str(&format!("<d:href>{}</d:href>", xml_escape(&session_href)));
+    let _ = write!(
+        body,
+        "<d:href>/remote.php/dav/uploads/{}/{}/</d:href>",
+        xml_escape(&session.raw_username),
+        xml_escape(upload_id)
+    );
     body.push_str("<d:propstat><d:prop>");
     body.push_str("<d:resourcetype><d:collection/></d:resourcetype>");
-    body.push_str(&format!(
-        "<d:getlastmodified>{}</d:getlastmodified>",
-        xml_escape(&session_last_modified)
-    ));
+    write_lastmodified(&mut body, listing.session_mtime as i64);
     body.push_str("</d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat>");
     body.push_str("</d:response>");
 
     // One entry per chunk file.
     for chunk in &listing.chunks {
-        let chunk_href = format!(
-            "/remote.php/dav/uploads/{}/{}/{}",
-            session.raw_username, upload_id, chunk.name
-        );
-        let chunk_modified = chrono::DateTime::<chrono::Utc>::from_timestamp(chunk.mtime as i64, 0)
-            .unwrap_or_else(chrono::Utc::now)
-            .to_rfc2822();
-
         body.push_str("<d:response>");
-        body.push_str(&format!("<d:href>{}</d:href>", xml_escape(&chunk_href)));
+        let _ = write!(
+            body,
+            "<d:href>/remote.php/dav/uploads/{}/{}/{}</d:href>",
+            xml_escape(&session.raw_username),
+            xml_escape(upload_id),
+            xml_escape(&chunk.name)
+        );
         body.push_str("<d:propstat><d:prop>");
         body.push_str("<d:resourcetype/>");
-        body.push_str(&format!(
+        let _ = write!(
+            body,
             "<d:getcontentlength>{}</d:getcontentlength>",
             chunk.size
-        ));
-        body.push_str(&format!(
-            "<d:getlastmodified>{}</d:getlastmodified>",
-            xml_escape(&chunk_modified)
-        ));
+        );
+        write_lastmodified(&mut body, chunk.mtime as i64);
         body.push_str("</d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat>");
         body.push_str("</d:response>");
     }