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/preview_handler.rs

@@ -144,7 +144,16 @@ pub async fn handle_preview(
     // compared it, so every revalidation re-ran the whole pipeline and
     // re-shipped the body (ROUND10). Authz already passed above; a 304
     // must never skip the Read check.
-    let etag = format!("\"thumb-{}-{:?}\"", object_id, thumb_size);
+    let etag = {
+        let s = thumb_size.as_str();
+        let mut e = String::with_capacity(9 + object_id.len() + s.len());
+        e.push_str("\"thumb-");
+        e.push_str(&object_id);
+        e.push('-');
+        e.push_str(s);
+        e.push('"');
+        e
+    };
     if let Some(inm) = headers.get(header::IF_NONE_MATCH)
         && let Ok(client_etag) = inm.to_str()
         && (client_etag == etag || client_etag == "*")