Replace catch-all proxy with dedicated routes, add 404 page

- Dedicated proxy routes for sessions, messages, search, memory, config
- Removes [...path] catch-all that conflicted with specific routes
- Session detail + delete proxy
- Custom 404 page matching design system

app/api/memory/route.ts

@@ -0,0 +1,27 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const BACKEND = process.env.HERMES_BACKEND_URL || "http://127.0.0.1:8643";
+
+async function proxy(method: string, req: NextRequest) {
+  const qs = req.nextUrl.search;
+  const body = method !== "GET" ? await req.text() : undefined;
+  try {
+    const res = await fetch(BACKEND + "/api/memory" + qs, {
+      method,
+      headers: body ? { "Content-Type": "application/json" } : {},
+      body,
+    });
+    const data = await res.text();
+    return new NextResponse(data, {
+      status: res.status,
+      headers: { "content-type": "application/json" },
+    });
+  } catch {
+    return NextResponse.json({ error: "backend unreachable" }, { status: 502 });
+  }
+}
+
+export async function GET(req: NextRequest) { return proxy("GET", req); }
+export async function POST(req: NextRequest) { return proxy("POST", req); }
+export async function PATCH(req: NextRequest) { return proxy("PATCH", req); }
+export async function DELETE(req: NextRequest) { return proxy("DELETE", req); }