chore: remove Sentry integration

src/lib/observability-contract.test.ts

@@ -0,0 +1,10 @@
+import { createRequire } from "node:module";
+import { describe, expect, it } from "vitest";
+
+describe("observability dependency contract", () => {
+	it("does not ship the Sentry SDK", () => {
+		const require = createRequire(import.meta.url);
+
+		expect(() => require.resolve("@sentry/nextjs")).toThrow();
+	});
+});