merge: bring gallery frontend branch up to date with goutamnextflow

goutamnextflow adopts @insignia/iios-messaging-ui (drops the bespoke
messenger/inbox/mail) and adds Org Settings → Integrations. Resolve against
the Smart Gallery work:
- dashboard.tsx: route messenger→MessengerSdk, inbox→InboxSdk, add settings→
  Settings (goutamnextflow) AND keep gallery→SmartGallery (ours). Drop the
  now-deleted Messenger/Inbox imports.
- next.config.ts / package.json: union transpilePackages + deps (keep
  @photo-gallery/sdk + ML deps AND @insignia/iios-messaging-ui).
- dashboard.css: keep both appended blocks (.gal* gallery + .settings-* org
  settings).

Gallery integrates with zero errors. Vendored @photo-gallery/sdk re-synced
(0-diff). Verified: tsc clean + `next build` compiles the whole merged app
(gallery AI routes + dashboard). The new @insignia/iios-messaging-ui private
dep is stubbed locally (see .claude/dev-scripts); it resolves on CI/Vercel.

next.config.ts

@@ -1,9 +1,9 @@
 import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
-  // Both SDKs ship ESM/TS source (their package `exports` point at src/), so Next
-  // must transpile them rather than treat them as prebuilt CJS.
-  transpilePackages: ["@abe-kap/appshell-sdk", "@photo-gallery/sdk"],
+  // The SDKs ship ESM/TS source (their `exports` point at src/), so Next must
+  // transpile them rather than treat them as prebuilt CJS.
+  transpilePackages: ["@abe-kap/appshell-sdk", "@insignia/iios-messaging-ui", "@photo-gallery/sdk"],
   // The browser calls the Shell BFF same-origin under /shell (so the HttpOnly
   // session cookie flows). We deliberately use /shell (NOT /api) to avoid
   // clobbering the existing /api/geo route. Point BFF_ORIGIN at the deployed BFF.