Deploy on DigitalOcean App Platform (GitHub-source build) + consolidate audit-fixes

Deploy config:
- .do/app.yaml: build the Dockerfile directly from GitHub (deploy_on_push) instead
  of a pre-built DOCR image; NEXT_PUBLIC_* set RUN_AND_BUILD_TIME with the
  propertymanagement.network domain so they bake into the client bundle; add
  custom domains block (apex + www); wire Sentry DSN (server + browser).

Included pending work from the audit-fixes branch:
- AI provider abstraction (OpenAI/Anthropic, admin-selectable; Anthropic default)
- Per-landlord e-signature (DocuSign OAuth + Dropbox Sign) + migration 0010
- Outbound webhooks / Zapier integration
- PayPal removal (Stripe-only billing)
- Storage hardening (fail-loud when Spaces unconfigured), security fixes

Verified: full production Docker build (same build-args as DO) passes clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/manifest.ts

@@ -12,11 +12,23 @@ export default function manifest(): MetadataRoute.Manifest {
     theme_color: "#09090b",
     icons: [
       {
-        src: "/logo-mark.png",
+        src: "/icon-192.png",
         type: "image/png",
-        sizes: "100x100",
+        sizes: "192x192",
         purpose: "any",
       },
+      {
+        src: "/icon-512.png",
+        type: "image/png",
+        sizes: "512x512",
+        purpose: "any",
+      },
+      {
+        src: "/icon-maskable-512.png",
+        type: "image/png",
+        sizes: "512x512",
+        purpose: "maskable",
+      },
     ],
   }
 }