feat(deps): Tier 2 UX polish — embla, lightbox, gestures, virtuoso, motion

Installs all five Tier 2 polish deps the audit flagged. Each integrates
where it adds concrete value today:

- **embla-carousel-react** — shadcn-style `<Carousel>` primitive in
  `src/components/ui/carousel.tsx`. Available for future berth/yacht
  photo galleries; no current call site beyond the primitive.
- **yet-another-react-lightbox** — wired into the image branch of
  `file-preview-dialog.tsx`. Clicking the preview image now opens a
  fullscreen lightbox with zoom/pan/keyboard nav. Lazy-loaded so the
  ~50kb only ships when a user actually previews an image.
- **@use-gesture/react** — `usePinch` on the PdfViewer's content
  pane for native pinch-zoom on tablets/phones. Clamped to the
  same [50%, 300%] range as the +/- buttons; desktop wheel still
  scrolls.
- **react-virtuoso** — installed but NOT wired. Inbox is naturally
  bounded by recent-notifications filter at ~10-20 items; ScrollArea
  handles it fine. Reserve for actual scale issues (admin audit log
  archive, etc.).
- **motion** — installed but NOT wired. Pipeline kanban uses
  dnd-kit's own transforms and conflicts with motion's layout
  animation. @formkit/auto-animate already handles list-mutation
  animations elsewhere. Available for opportunistic adoption when
  a polish surface emerges that the existing libraries don't cover.

Verified: tsc clean, vitest 1315/1315, next build green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -64,6 +64,7 @@
     "@tanstack/react-table": "^8.21.3",
     "@tanstack/react-virtual": "^3.13.24",
     "@types/pdfkit": "^0.17.6",
+    "@use-gesture/react": "^10.3.1",
     "archiver": "^7.0.1",
     "better-auth": "^1.6.11",
     "browser-image-compression": "^2.0.2",
@@ -73,6 +74,7 @@
     "cmdk": "^1.1.1",
     "date-fns": "^4.1.0",
     "drizzle-orm": "^0.45.2",
+    "embla-carousel-react": "^8.6.0",
     "imapflow": "^1.3.3",
     "ioredis": "^5.10.1",
     "iso-3166-2": "^1.0.0",
@@ -82,6 +84,7 @@
     "lucide-react": "^1.14.0",
     "mailparser": "^3.9.8",
     "minio": "^8.0.7",
+    "motion": "^12.38.0",
     "next": "16.2.6",
     "next-intl": "^4.11.2",
     "next-themes": "^0.4.6",
@@ -105,6 +108,7 @@
     "react-number-format": "^5.4.5",
     "react-pdf": "^10.4.1",
     "react-resizable-panels": "^3.0.6",
+    "react-virtuoso": "^4.18.7",
     "recharts": "^3.8.1",
     "sharp": "^0.34.5",
     "socket.io": "^4.8.3",
@@ -118,6 +122,7 @@
     "unpdf": "^1.6.2",
     "vaul": "^1.1.2",
     "web-vitals": "^5.2.0",
+    "yet-another-react-lightbox": "^3.32.0",
     "zod": "^4.4.3",
     "zustand": "^5.0.13"
   },