feat: add better auth sqlite runtime and server-side session flow

app/api/auth/[...all]/route.ts

@@ -0,0 +1,7 @@
+import { toNextJsHandler } from "better-auth/next-js";
+import { auth } from "@/server/auth/auth";
+
+export const runtime = "nodejs";
+
+export const { GET, POST } = toNextJsHandler(auth);
+

app/api/health/live/route.ts

@@ -0,0 +1,8 @@
+export const runtime = "nodejs";
+
+export function GET() {
+  return Response.json({
+    status: "ok",
+    timestamp: new Date().toISOString(),
+  });
+}

app/api/health/ready/route.ts

@@ -0,0 +1,16 @@
+import { checkReadiness } from "@/server/db/health";
+
+export const runtime = "nodejs";
+
+export function GET() {
+  const readiness = checkReadiness();
+
+  return Response.json(
+    {
+      status: readiness.ok ? "ok" : "unhealthy",
+      checks: readiness.checks,
+      timestamp: new Date().toISOString(),
+    },
+    { status: readiness.ok ? 200 : 503 },
+  );
+}