Add a signerMiddleware

src/middleware/signerMiddleware.ts

@@ -0,0 +1,13 @@
+import { AppMiddleware } from '@/app.ts';
+import { APISigner } from '@/signers/APISigner.ts';
+
+/** Make a `signer` object available to all controllers, or unset if the user isn't logged in. */
+export const signerMiddleware: AppMiddleware = async (c, next) => {
+  try {
+    c.set('signer', new APISigner(c));
+  } catch {
+    // do nothing
+  }
+
+  await next();
+};