perf: round 4 — one-pass row paths, drive-selector cache, CalDAV single-parse, streamed Azure, batched hydration

Nine benchmark-gated changes (benches/ROUND4.md; every one ships with a
BEFORE/AFTER bench + equivalence gate, rollback rule as ROUND2/3):

- Row→entity path build: one-pass StoragePath::from_folder_and_name /
  from_joined + normalize_storage_name_owned + alloc-free Display —
  743→417 ns/file-row (1.78x), −5 allocs/row on every listing surface.
- WebDAV drive-selector: per-user readable_cache (single-flight, 30 s
  TTL, explicit invalidation incl. membership + group changes) replaces
  the grants join per request — 441 µs → 0.8 µs (~550x), 0 queries warm.
- CalDAV from_ical/update_ical_data: 8 full IcalParser runs per VEVENT
  → 1 (7.1x per PUT, 4.4x on 50-event imports); alloc-free split_vevents,
  chunk scan without the whole-body uppercase copy (1.4x), borrowed-key
  UID grouping (1.3x), REPORT props no longer cloned.
- PROPFIND emit: partition Vecs dropped (single-pass 404 list) + stack
  rendered RFC 3339/2822 dates, sizes, quoted etags (common::fmt,
  chrono-byte-identical, sweep-tested) on both DAV surfaces — 1.22x
  per page, 17.9→12.0 allocs/row.
- Grant-listing hydration: calendars/address books/playlists batch
  hydrate via = ANY($1) — 15 serial queries → 1 (~13x per sync poll).
- user-flags cache: get→insert → try_get_with single-flight (32→1
  queries per cold herd).
- Azure downloads: whole-blob Vec buffering → streamed SDK pages —
  TTFB 349→4 ms (87x), peak heap 480→1.9 MiB (254x) on 256 MiB blobs;
  new OXICLOUD_AZURE_ENDPOINT_URL override (Azurite/bench hook).
- Face indexing: unbounded per-image tokio::spawn → core-count
  semaphore, permit before blob read — peak heap 1175→176 MiB (6.7x).

Checks: cargo fmt, clippy --all-features --all-targets -D warnings,
cargo test --workspace (523 passed) + --features test_utils. hurl API
suite and dockerized integration DB not runnable in this environment —
left to CI.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017aJu9ghvuT8WqC31ZEGTBA

src/infrastructure/repositories/pg/calendar_pg_repository.rs

@@ -138,6 +138,42 @@ impl CalendarRepository for CalendarPgRepository {
         Ok(calendar)
     }
 
+    async fn find_calendars_by_ids(&self, ids: &[Uuid]) -> CalendarRepositoryResult<Vec<Calendar>> {
+        if ids.is_empty() {
+            return Ok(Vec::new());
+        }
+        let rows = sqlx::query(
+            r#"
+            SELECT id, name, owner_id, description, color, is_public, created_at, updated_at
+            FROM caldav.calendars
+            WHERE id = ANY($1)
+            "#,
+        )
+        .bind(ids)
+        .fetch_all(&*self.pool)
+        .await
+        .map_err(|e| {
+            DomainError::database_error(format!("Failed to get calendars by ids: {}", e))
+        })?;
+
+        rows.iter()
+            .map(|row| {
+                Calendar::with_id(
+                    row.get("id"),
+                    row.get("name"),
+                    row.get("owner_id"),
+                    row.get("description"),
+                    row.get("color"),
+                    row.get("created_at"),
+                    row.get("updated_at"),
+                )
+                .map_err(|e| {
+                    DomainError::database_error(format!("Failed to create calendar object: {}", e))
+                })
+            })
+            .collect()
+    }
+
     async fn list_calendars_by_owner(
         &self,
         owner_id: Uuid,