perf: round 12 — auth write-path narrowing, fused quota gate, moka blob-cache index, media single-read, sized listing JSON

Benchmark-gated round (benches/ROUND12.md; every change ships with a
BEFORE/AFTER harness + equivalence gates, one candidate rejected by its
own bench):

DB / query shapes (bench_round12_queries):
- NC sharee search: username-only projection instead of the 21-column row
  (incl. the <=512 KiB avatar) per match, + gin_trgm_ops indexes on
  auth.users for the leading-wildcard ILIKE (4.98x; 54.7x with index).
- Password login: delete the redundant full-row update_user — create_session
  already stamps last_login_at in its own txn (4.45x per login).
- Email-verified stamp: narrow conditional UPDATE (8.9x); OIDC repeat login
  now compares profile state in memory and issues ZERO queries when nothing
  changed (was: full 17-column rewrite per login).
- Refresh rotation: revoke+insert+stamp fused into one transaction via new
  rotate_session port method (1.18x).
- WOPI CheckFileInfo / authorize_wopi_access: require(Read) + get_file +
  check(Update) overlapped with tokio::join!, original result precedence
  (cold 1.34x).
- Upload quota gate: user-envelope + drive-cap checks fused into ONE
  round-trip (check_upload_quotas) — the NC chunked PUT pays this per
  chunk (1.81x, 2 -> 1 queries/chunk); shared verdict evaluators keep
  error shapes byte-identical.

CPU / allocs (bench_round12_micro):
- sized_json: pre-sized listing serialization replacing axum Json's 128 B
  seed + doubling-realloc chain on files/folder-resources/photos/search
  responses (1.40x, 13 -> 2 allocs per 500-row page; byte-identical).
- Security headers: 4 SetResponseHeaderLayer folded into the CSP middleware
  pass (5 layers -> 1; 1.43x per request, -26 allocs; header set gated
  byte-identical incl. 304s).
- Media capture-metadata: single-read extraction — nom-exif now parses the
  buffer kamadak already read (zero-copy Bytes) and videos open once with a
  kind() dispatch; per-image opens 2-3 -> 1 (1.44x warm geomean, 1.6-3.2x
  cold cache; extraction outputs gated identical incl. the MIME-mislabel
  track fallback).
- Chunked-upload session ops: owner gate folded into the operation's own
  DashMap lookup + stack-encoded uuid compare (5 -> 3 lookups, -2 allocs,
  1.28x per chunk).

Blob cache (bench_blob_cache_index + round-3 regression guard):
- CachedBlobBackend index: tokio::sync::Mutex<LruCache> -> moka::sync::Cache
  with byte weigher. The mutex serialized every cached chunk read and scaled
  NEGATIVELY (2.08 -> 1.07 Mops/s from 1 -> 2 readers); moka probes are
  lock-free (2.17x at K=2). Byte budget now enforced by moka (manual
  current_size + collect_evictions machinery deleted); eviction listener
  unlinks size-evicted files only (Replaced entries keep their file —
  gated). Single-flight miss gate unchanged (16 concurrent misses -> 1
  fetch re-verified via the round-3 harness).
- put_blob now populates the cache BEFORE the inner backend consumes the
  source file (the old order failed 100% of the time — local renames,
  S3/Azure delete the source — so the first read after a whole-file put
  re-downloaded from the remote); inner-put failure invalidates the entry.

Frontend (vitest gates):
- List-view thumbnails request the 150px icon rendition instead of 400px
  preview into a 40px slot (~7.1x fewer pixels, ~4-5x fewer bytes per
  thumbnail across list views); grid keeps preview.

Rejected by its own bench (kept as evidence in bench_round12_micro §2):
- Single-pass compression predicate: the monomorphized And-chain already
  costs ~4.6 ns / 0 allocs total; the fused node measured within noise.

New migration: 20260719000000_users_search_trgm.sql (trgm indexes).
Deferred with prepared design: grouped file/grid view virtualization
(single-VirtualRows flatten, the photos pattern) — next round's headline.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BfidAJD5AHw23jtvBUNamB

Cargo.toml

@@ -354,6 +354,31 @@ name = "bench_micro_allocs"
 path = "examples/bench_micro_allocs.rs"
 required-features = ["bench"]
 
+# Round-12 battery ────────────────────────────────────────────────────────────
+
+# Round-12 query-shape pack — sharee narrow read + trgm, login/email stamp
+# narrowing, session-rotation fused txn, WOPI triple join!, fused quota pair
+# (needs the dev Postgres up).
+[[example]]
+name = "bench_round12_queries"
+path = "examples/bench_round12_queries.rs"
+required-features = ["bench"]
+
+# Round-12 CPU/alloc micro-pack — sized listing JSON, single-pass compression
+# predicate, fused security-header middleware, media single-read extraction,
+# chunked-session fused lookups. No Postgres.
+[[example]]
+name = "bench_round12_micro"
+path = "examples/bench_round12_micro.rs"
+required-features = ["bench"]
+
+# Blob-cache index — Mutex<LruCache> vs moka byte-weigher (index scaling,
+# warm-hit reads, eviction-unlink + single-flight safety gates). No Postgres.
+[[example]]
+name = "bench_blob_cache_index"
+path = "examples/bench_blob_cache_index.rs"
+required-features = ["bench"]
+
 # Round-11 battery ────────────────────────────────────────────────────────────
 
 # Round-11 CPU/alloc micro-pack — download DTO hand-off, Last-Modified stack