perf: keyset/LATERAL SQL shapes, auth+blob-cache single-flight, spool buffers, DTO interning

Round 3 of benchmark-gated optimizations (benches/ROUND3.md; every change
gated by a before/after benchmark — an AFTER that did not beat its BEFORE
was to be rolled back; none needed it. Equivalence gates assert identical
row sequences / byte-identical output on every behavior-preserving rewrite):

DB hot paths (local PG16, EXPLAIN-verified):
- Web-UI listing (list_resources_paged): cursor pushed INSIDE the
  folders/files UNION-ALL branches as sargable row-value comparisons with
  per-branch ORDER/LIMIT + two partial expression indexes
  (folder_id, LOWER(name), id). 20k-entry folder: 26.6 -> 1.3 ms/page
  (19.5x); other sort modes at parity or better. New migration
  20260918000000. [benches/LISTING-KEYSET.md section in ROUND3]
- Photos timeline (list_media_files): per-drive CROSS JOIN LATERAL top-N
  on the timeline index, joins moved above the top-N. 50k-photo library:
  97.4 -> 1.6 ms/page (55.7x). The old "LIMIT stops the scan early"
  comment was refuted by EXPLAIN.
- PROPFIND sub-folders (both DAV surfaces): keyset list_folders_batch off
  idx_folders_unique_name replaces COUNT(*) OVER() + LIMIT/OFFSET
  (5k dirs: 79.7 -> 17.9 ms full walk, 4.5x).

Concurrency:
- Basic-auth cache single-flight (moka try_get_with): 8 concurrent DAV
  connections at TTL expiry paid 8 Argon2id runs (2.6 s CPU + 8x64 MiB);
  now 1 (300 ms). Failed verifications remain uncached.
- CachedBlobBackend per-hash single-flight + unique tmp names: 16
  concurrent cold readers = 16 full remote downloads racing truncating
  writes on ONE deterministic .tmp (corruptible cache); now 1 download
  (16x less egress, 2.8x wall on a shared link) and torn files can never
  be renamed into the cache.

I/O and allocations:
- Chunk-assembly reads 64K -> 512K buffers (2.3x, 8x fewer syscalls);
  chunk-spool writes via BufWriter 512K (5.6x, 32x fewer syscalls).
- S3/Azure put_blob_from_bytes_unsynced overrides: dedup settle no longer
  pays a HEAD probe per new chunk (2 RTT -> 1, 1.8x); Azure stops copying
  every chunk (Bytes -> Body, -0.44 ms - 4 MiB alloc per 4 MiB chunk).
- Entity->DTO mapping: Arc<str> interning of closed-set display fields +
  common MIMEs, 1-alloc etag/size formatting, FolderDto moves instead of
  clones. File row: 11 -> 4 allocs; folder row: 11.8 -> 1 (2.1x faster).
- CardDAV REPORT: deleted dead per-contact vCard pre-generation and the
  O(N^2) uid scan whose result was discarded (5k contacts: 55.7 -> 5.7 ms,
  9.8x); byte-identical XML asserted.
- Search-results cache: byte weigher + 32 MiB budget
  (OXICLOUD_SEARCH_CACHE_MAX_BYTES) replaces the 1000-ENTRY cap that let
  ~300 MiB of enriched rows sit in RSS; read latency parity.
- Dropped aws-config + aws-smithy-types (zero references; -82 dep-graph
  nodes, three SDK stacks gone from every build). tokio "process" is now
  an explicit feature (was enabled transitively by aws-config).

Frontend:
- Cached Intl.DateTimeFormat keyed by (locale, options) in formatDate and
  4 sibling callsites: 20k dates 2612 -> 51 ms (51.6x); vitest gate
  asserts output identity across locales and a 3x floor.

Validation: cargo fmt + clippy --all-features --all-targets -D warnings
clean; 518 unit + 548 integration-cfg tests green; new-shape endpoints
smoke-tested end-to-end over HTTP (all 5 listing sort modes with cursor
walks, WebDAV PROPFIND Depth-1, photos timeline, Basic-auth DAV login);
frontend npm run check clean, new vitest gates green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EBsU2qEzny3A8WQUEuMNCr

Cargo.lock

@@ -341,37 +341,6 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
-[[package]]
-name = "aws-config"
-version = "1.8.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e33f815b73a3899c03b380d543532e5865f230dce9678d108dc10732a8682275"
-dependencies = [
- "aws-credential-types",
- "aws-runtime",
- "aws-sdk-sso",
- "aws-sdk-ssooidc",
- "aws-sdk-sts",
- "aws-smithy-async",
- "aws-smithy-http",
- "aws-smithy-json",
- "aws-smithy-runtime",
- "aws-smithy-runtime-api",
- "aws-smithy-schema",
- "aws-smithy-types",
- "aws-types",
- "bytes",
- "fastrand 2.4.1",
- "hex",
- "http 1.4.0",
- "sha1 0.10.6",
- "time",
- "tokio",
- "tracing",
- "url",
- "zeroize",
-]
-
 [[package]]
 name = "aws-credential-types"
 version = "1.2.14"
@@ -470,82 +439,6 @@ dependencies = [
  "url",
 ]
 
-[[package]]
-name = "aws-sdk-sso"
-version = "1.102.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c82b3ac19f1431854f7ace3a7531674633e286bfdde21976893bfee36fd493b"
-dependencies = [
- "arc-swap",
- "aws-credential-types",
- "aws-runtime",
- "aws-smithy-async",
- "aws-smithy-http",
- "aws-smithy-json",
- "aws-smithy-observability",
- "aws-smithy-runtime",
- "aws-smithy-runtime-api",
- "aws-smithy-types",
- "aws-types",
- "bytes",
- "fastrand 2.4.1",
- "http 0.2.12",
- "http 1.4.0",
- "regex-lite",
- "tracing",
-]
-
-[[package]]
-name = "aws-sdk-ssooidc"
-version = "1.104.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "321000d2b4c5519ee573f73167f612efd7329322d9b26969ad1979f0427f1913"
-dependencies = [
- "arc-swap",
- "aws-credential-types",
- "aws-runtime",
- "aws-smithy-async",
- "aws-smithy-http",
- "aws-smithy-json",
- "aws-smithy-observability",
- "aws-smithy-runtime",
- "aws-smithy-runtime-api",
- "aws-smithy-types",
- "aws-types",
- "bytes",
- "fastrand 2.4.1",
- "http 0.2.12",
- "http 1.4.0",
- "regex-lite",
- "tracing",
-]
-
-[[package]]
-name = "aws-sdk-sts"
-version = "1.107.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d0d328ba962af23ecfa3c9f23b98d3d35e325fa218d7f13d17a6bf522f8a560"
-dependencies = [
- "arc-swap",
- "aws-credential-types",
- "aws-runtime",
- "aws-smithy-async",
- "aws-smithy-http",
- "aws-smithy-json",
- "aws-smithy-observability",
- "aws-smithy-query",
- "aws-smithy-runtime",
- "aws-smithy-runtime-api",
- "aws-smithy-types",
- "aws-smithy-xml",
- "aws-types",
- "fastrand 2.4.1",
- "http 0.2.12",
- "http 1.4.0",
- "regex-lite",
- "tracing",
-]
-
 [[package]]
 name = "aws-sigv4"
 version = "1.4.5"
@@ -688,16 +581,6 @@ dependencies = [
  "aws-smithy-runtime-api",
 ]
 
-[[package]]
-name = "aws-smithy-query"
-version = "0.60.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a56d79744fb3edb5d722ef79d86081e121d3b9422cb209eb03aea6aa4f21ebd"
-dependencies = [
- "aws-smithy-types",
- "urlencoding",
-]
-
 [[package]]
 name = "aws-smithy-runtime"
 version = "1.11.3"
@@ -4231,9 +4114,7 @@ dependencies = [
  "async-stream",
  "async-trait",
  "async_zip",
- "aws-config",
  "aws-sdk-s3",
- "aws-smithy-types",
  "axum",
  "azure_core",
  "azure_storage",