perf: round 13 — grouped-view virtualization, notification/login query narrowing, HTTP dedup, locale precompute

Benchmark-gated (BEFORE/AFTER + equivalence/safety gate per change), same
discipline as rounds 2-12. Full write-up in benches/ROUND13.md.

Shipped:
- V1 Grouped views windowed (files route + ResourceList). The grid arm was
  the last unwindowed path (trash is grouped-by-default in grid): each
  swimlane now feeds its own VirtualList, outer container a flex stack.
  vitest gate: 800-item grouped grid mounts <120 .file-item (was 800).
- Q1 get_users_by_ids drops the <=512 KiB avatar image + ui_preferences
  JSONB (notification path never reads them). 30-member fan-out 8.60 ->
  0.25 ms (34.3x), ~7.7 MB off the wire.
- Q2 Login provisioning is_empty() -> SELECT EXISTS for calendar + address
  book (every login). 0.193 -> 0.170 ms, widens with owned-row count.
- Q3 Recent-access prunes only when the upsert inserted (RETURNING xmax=0)
  — a re-access can't grow the set. 0.567 -> 0.324 ms (1.75x).
- L1 Locale supported-codes precomputed once vs rebuilt per anonymous
  request. 616 -> 17.3 ns (35.7x), 18 -> 1 allocs.
- H1 Duplicate /api TraceLayer removed (global stack already wraps it).
  1.86 -> 1.42 us/request, -6 allocs.
- H2 client_ip span field: borrow-only ClientIpDisplay vs owned String.
  187 -> 173 ns, -1 alloc.

Not shipped (discipline): the "media hooks read the blob 3x" lead was a
correctness bug, not a perf dup — the raw-path metadata/faces readers
resolve only for local+unencrypted+single-chunk blobs and silently produce
nothing otherwise. Flagged for maintainers; routing through read_blob_bytes
is a correctness fix (perf-neutral-to-negative), not a benchmark-gated
perf change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BfidAJD5AHw23jtvBUNamB

src/interfaces/api/routes.rs

@@ -10,7 +10,6 @@ use axum::{
 };
 use serde_json::json;
 use std::sync::Arc;
-use tower_http::trace::TraceLayer;
 use utoipa::OpenApi;
 
 /// Liveness probe — returns 200 if the process is running, no DB check.
@@ -672,12 +671,14 @@ pub fn create_api_routes(app_state: &Arc<AppState>) -> Router<Arc<AppState>> {
     // them on every overlapping request.
     router = router.route("/{*rest}", any(api_not_found));
 
-    // Compression is applied once, globally, in `main.rs` with a content-type
-    // aware predicate that skips already-compressed media. Re-applying it here
-    // would double-wrap `/api`: this inner layer (no predicate) would compress
-    // media downloads, burning CPU for ~0 gain and stripping `Content-Length`.
-    // So this router only adds tracing; compression is the global layer's job.
-    router.layer(TraceLayer::new_for_http())
+    // No per-router layers: the global `TraceLayer` + request-id stack in
+    // `main.rs` wraps the whole app (this `/api` router is nested into it),
+    // so a second `TraceLayer` here just double-wrapped every `/api`
+    // request in a redundant span + response-future poll (benches/ROUND13.md
+    // §H1). Compression is likewise the global layer's job — re-applying it
+    // here (no predicate) would compress media downloads, burning CPU for
+    // ~0 gain and stripping `Content-Length`.
+    router
 }
 
 /// Catch-all 404 for unknown `/api/*` paths. Pure log-anchoring