perf: eliminate N+1 hot-path queries, cache immutable lookups, stop re-compressing compressed bytes

Every change is benchmark-verified (harness + before/after numbers in
benches/, measured on this branch; reproduction commands in each doc):

DAV / sync-client hot paths
- PROPFIND dead-properties: one = ANY($1) query per 500-child page instead
  of one sequential query per child, and indexable `=` predicates instead
  of IS NOT DISTINCT FROM (seq scans). 2,000-child folder: 1.07-4.54 s of
  DB chatter -> 4-6 ms (258-773x). Applied to native + NC PROPFIND and
  both NC REPORT handlers. [benches/DEAD-PROPS.md]
- Folder paging: keyset cursor (name > $last) + new partial index
  (folder_id, name) replaces LIMIT/OFFSET full-folder rescan per page.
  Full 20k-file walk: 1266 ms -> 77 ms (16.5x). New migration
  20260917000000. [benches/PROPFIND-PAGING.md]
- NC chroot / default-drive resolution: moka caches (30 s TTL, explicit
  invalidation on drive mutations) for find_default_for_user and the
  markerless chroot FolderDto. 2 uncached queries + 2 pool checkouts per
  NC/WebDAV/WOPI request -> sub-us moka hit (p50 0.7-3.6 ms -> ~1 us).
  [benches/CHROOT-CACHE.md]
- Quota: PROPFINDs whose prop list never names a quota prop skip the
  2-query resolution entirely (wants_quota()); the remaining lookups read
  2 columns instead of the full auth.users row with its <=512 KiB avatar
  (11-16x, p50 3.4 ms -> 0.29 ms). Same narrow read now gates every
  upload quota check. [benches/QUOTA-PATH.md]

CPU on the request path
- ZIP exports (folder download, share ZIP, batch download): entries whose
  MIME says already-compressed (JPEG/MP4/zip/pdf/...) are Stored instead
  of Deflate - deflate ran inline on the tokio writer task at ~41 MB/s
  for ~0% size gain. Mixed media corpus: 4.31x wall and CPU, archive size
  unchanged. Shared predicate in common::mime_detect. [benches/ZIP-MEDIA.md]
- Compression layers: tower-http's default maps to Brotli QUALITY 11
  (verified in brotli-8.0.2 source and empirically: 90 ms per 64 KiB JSON
  response, 1.3 s per 700 KiB bundle). Both layers pinned to Precise(4):
  99x less CPU for ~15% more bytes. SPA assets are now precompressed at
  build time (scripts/precompress.mjs, 77% smaller) and served via
  ServeDir::precompressed_br/gzip: 2016x less per-request work, and
  clients get the better q11 bytes. [benches/STATIC-PRECOMPRESSED.md]

Batched / cached backend paths [benches/NPLUS1-AND-CACHES.md]
- Content-search ReBAC re-verification: new
  AuthorizationEngine::check_files_read_batch (default = old loop;
  PgAclEngine override batches drive resolution + reuses role cache).
  200 sequential point SELECTs per search -> 1-2 queries.
- Batch-ZIP subtree downloads: drop per-file re-authz + per-file Recent
  recording (2 writes/file) for subtree entries already authorized at the
  root - mirrors the native folder-download path. ~6,000 statements
  removed from a 2,000-file archive.
- CDC chunk manifests: immutable by content address, now moka-cached
  (weight-bounded 32 MiB, 60 s TTL, positive-only, invalidated on delete)
  - removes one manifest query (p50 0.44-4.4 ms) from every stream,
  range and full blob read.
- People tab: grouped COUNT + batched cover lookup instead of dragging
  every face row with its 2 KiB embedding (10k faces: 30.4 ms & 21 MB ->
  3.8 ms & 1.3 KB, 8.1x); merge() is one set-based UPDATE.
  [benches/PEOPLE-LIST.md]
- Photos timeline cursor: raw timestamptz comparison instead of
  EXTRACT(EPOCH ...) wrapper + IS NULL OR disjunction - cursor is an
  index boundary again, deep scroll stops re-scanning skipped rows.
- Public share landing: one atomic UPDATE ... access_count + 1 (was
  SELECT + full-row write-back: racy, lost updates, clobbered concurrent
  owner edits) - 3 round-trips -> 2 per visit.
- move_to_trash: dead full-entity SELECT feeding a documented no-op
  removed from both branches; dead fields dropped from TrashService.
- NFC normalization: is_nfc_quick fast path skips the decompose/recompose
  state machine for the ~100% already-NFC case (every row loaded from PG).

Frontend
- Large folders paint after page one (~200 items) via fetchFolderListing's
  new onPage hook instead of waiting for every sequential page.
- Tested-and-reverted (kept for the record): cached Intl.Collator for name
  sorts - vitest showed it 2x SLOWER than V8's argument-less localeCompare
  fast path (5.6 ms vs 12.1 ms / 5k names). Sort order untouched.

New bench harnesses under examples/ (bench feature): zip_media,
dead_props, chroot_cache, quota_path, people_list, propfind_paging,
static_precompress.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBK1RdtzyP6759Muqe1K1w

benches/STATIC-PRECOMPRESSED.md

@@ -0,0 +1,56 @@
+# Static assets & API responses — precompressed siblings + explicit Brotli level
+
+Two related findings, one root cause: tower-http's `CompressionLayer` default
+maps to **Brotli QUALITY 11** (`async-compression Level::Default` →
+`BrotliEncoderParams::default()`, brotli-8.0.2 `encode.rs:323` — verified in
+source and empirically below). Quality 11 is a deploy-time setting; it was
+running per request on:
+
+- every SPA asset (`interfaces/web/mod.rs` layer): ~1.3 s CPU per 700 KiB
+  bundle per request;
+- every compressible API response (`main.rs` global layer): ~90 ms CPU per
+  64 KiB JSON response.
+
+Changes:
+
+1. **Precompressed statics.** `frontend/scripts/precompress.mjs` (build step,
+   node:zlib only) emits `.br`/`.gz` siblings for text assets; `ServeDir` now
+   uses `precompressed_br()/precompressed_gzip()` — a request costs a file
+   read, and clients get the *better* q11 bytes, paid once per deploy
+   (~1.4 s for the whole bundle).
+2. **Explicit level 4** on both `CompressionLayer`s
+   (`CompressionLevel::Precise(4)`) — the on-the-fly fallback for statics
+   without siblings, and the global API layer.
+
+## Reproduce
+
+```bash
+cargo run --release --features bench --example bench_static_precompress
+# tunables: BENCH_ASSET_KB=700 BENCH_REPS=30
+```
+
+## Results (4 cores, this container)
+
+**Per-request cost, 700 KiB JS-like asset (94 % compressible):**
+
+| mode                        | ms/request | speedup |
+|-----------------------------|-----------:|--------:|
+| BEFORE — on-the-fly Brotli  |   1,324.31 |   1.0×  |
+| AFTER — precompressed read  |      0.657 | **2016×** |
+
+**Brotli level sweep, 64 KiB JSON-like API response:**
+
+| level                   | ms/resp | out KiB |
+|-------------------------|--------:|--------:|
+| Default (= quality 11!) |   90.10 |     5.4 |
+| **Precise(4)** (chosen) |    0.91 |     6.2 |
+| Fastest                 |    0.15 |     9.3 |
+
+- Statics: 3 orders of magnitude less CPU per request, while shipping
+  *smaller* bytes than the runtime default would at any reasonable level.
+- API responses: **99× less CPU** for ~15 % more bytes (5.4 → 6.2 KiB) —
+  `Precise(4)` is the classic dynamic-content operating point; `Fastest`
+  gives up too much density (9.3 KiB).
+- Historical note: an earlier review round REFUTED the "default is q11"
+  claim twice; the source line and the 90 ms/64 KiB measurement above settle
+  it the other way. Measure before believing — in both directions.