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

src/infrastructure/repositories/pg/user_pg_repository.rs

@@ -1067,6 +1067,81 @@ impl UserStoragePort for UserPgRepository {
             .map_err(DomainError::from)
     }
 
+    async fn search_usernames(
+        &self,
+        query: &str,
+        limit: i64,
+        include_external: bool,
+    ) -> Result<Vec<Option<String>>, DomainError> {
+        // Same predicate / order / limit as `search_users`, username-only
+        // projection — the sharee autocomplete path reads nothing else, and
+        // the wide row drags the avatar `image` per matched user.
+        let pattern = format!("%{}%", query);
+        let rows = sqlx::query(
+            r#"
+            SELECT username
+            FROM auth.users
+            WHERE (username ILIKE $1 OR email ILIKE $1)
+              AND ($3 OR is_external = FALSE)
+            ORDER BY username
+            LIMIT $2
+            "#,
+        )
+        .bind(&pattern)
+        .bind(limit)
+        .bind(include_external)
+        .fetch_all(&*self.pool)
+        .await
+        .map_err(Self::map_sqlx_error)
+        .map_err(DomainError::from)?;
+        Ok(rows.into_iter().map(|row| row.get("username")).collect())
+    }
+
+    async fn mark_email_verified(&self, user_id: Uuid) -> Result<(), DomainError> {
+        // SQL twin of `User::mark_email_verified` — stamps once, keeps the
+        // first timestamp, and touches only the two columns involved.
+        sqlx::query(
+            r#"
+            UPDATE auth.users
+            SET email_verified_at = NOW(), updated_at = NOW()
+            WHERE id = $1 AND email_verified_at IS NULL
+            "#,
+        )
+        .bind(user_id)
+        .execute(&*self.pool)
+        .await
+        .map_err(Self::map_sqlx_error)
+        .map_err(DomainError::from)?;
+        Ok(())
+    }
+
+    async fn sync_oidc_login_profile(
+        &self,
+        user_id: Uuid,
+        image: Option<&str>,
+    ) -> Result<(), DomainError> {
+        // `IS DISTINCT FROM` guard (the `update_storage_usage` pattern): the
+        // common repeat-login case — same IdP avatar, already verified —
+        // writes nothing at all (no dead tuple, no WAL).
+        sqlx::query(
+            r#"
+            UPDATE auth.users
+            SET image = $2,
+                email_verified_at = COALESCE(email_verified_at, NOW()),
+                updated_at = NOW()
+            WHERE id = $1
+              AND (image IS DISTINCT FROM $2 OR email_verified_at IS NULL)
+            "#,
+        )
+        .bind(user_id)
+        .bind(image)
+        .execute(&*self.pool)
+        .await
+        .map_err(Self::map_sqlx_error)
+        .map_err(DomainError::from)?;
+        Ok(())
+    }
+
     async fn list_users_by_role(&self, role: &str) -> Result<Vec<User>, DomainError> {
         UserRepository::list_users_by_role(self, role)
             .await