Add initial webmanifest controller

src/controllers/manifest.ts

@@ -0,0 +1,23 @@
+import { AppController } from '@/app.ts';
+import { Storages } from '@/storages.ts';
+import { WebManifestCombined } from '@/types/webmanifest.ts';
+import { getInstanceMetadata } from '@/utils/instance.ts';
+
+export const manifestController: AppController = async (c) => {
+  const meta = await getInstanceMetadata(await Storages.db(), c.req.raw.signal);
+
+  const manifest: WebManifestCombined = {
+    name: meta.name,
+    short_name: meta.name,
+    start_url: '/',
+    display: 'standalone',
+    scope: '/',
+    description: meta.about,
+  };
+
+  return c.json(manifest, {
+    headers: {
+      'Content-Type': 'application/manifest+json',
+    },
+  });
+};