Move Proxmox and Synology to their own top-level pages

Same move as Docker/Tailscale/Semaphore/Gitea: each was buried inside
the generic Integrations browsing view. Give them dedicated pages too
— this was the last pair, so every integration type with a browsing UI
now has its own page.

New web/src/pages/{Proxmox,Synology}.tsx reuse the existing, unchanged
API routes and adapters (no server changes) with their own integration
picker scoped to just that type. Added matching nav items and routes.
Synology stays read-only, matching its original design.

Removed the corresponding state/handlers/tables from Integrations.tsx
(296 lines). It's now down to just the "Manage integrations" CRUD
table plus a browsing dropdown whose six branches are all redirects to
the type's own page — genuinely pointless now that every type has
moved out, worth simplifying separately.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/App.tsx

@@ -15,6 +15,8 @@ import Docker from "./pages/Docker";
 import Tailscale from "./pages/Tailscale";
 import Semaphore from "./pages/Semaphore";
 import Gitea from "./pages/Gitea";
+import Proxmox from "./pages/Proxmox";
+import Synology from "./pages/Synology";
 import Settings from "./pages/Settings";
 import NotificationSettings from "./pages/settings/NotificationSettings";
 import BadgeSettings from "./pages/settings/BadgeSettings";
@@ -80,6 +82,8 @@ export default function App() {
         <Route path="/tailscale" element={<Tailscale user={user} />} />
         <Route path="/semaphore" element={<Semaphore user={user} />} />
         <Route path="/gitea" element={<Gitea user={user} />} />
+        <Route path="/proxmox" element={<Proxmox user={user} />} />
+        <Route path="/synology" element={<Synology user={user} />} />
         <Route
           path="/users"
           element={