feat: initialize thoughts-frontend with Next.js, TypeScript, and ESLint

- Add ESLint configuration for Next.js and TypeScript support.
- Create Next.js configuration file with standalone output option.
- Initialize package.json with scripts for development, build, and linting.
- Set up PostCSS configuration for Tailwind CSS.
- Add SVG assets for UI components.
- Create TypeScript configuration for strict type checking and module resolution.

thoughts-backend/tests/api/user.rs

@@ -0,0 +1,36 @@
+use axum::{http::StatusCode, Router};
+use http_body_util::BodyExt;
+use serde_json::Value;
+
+use utils::testing::{make_get_request, make_post_request};
+
+pub(super) async fn test_post_users(app: Router) {
+    let response = make_post_request(app, "/users", r#"{"username": "test"}"#.to_owned()).await;
+    assert_eq!(response.status(), StatusCode::CREATED);
+
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    assert_eq!(&body[..], br#"{"id":1,"username":"test"}"#);
+}
+
+pub(super) async fn test_post_users_error(app: Router) {
+    let response = make_post_request(app, "/users", r#"{"username": "1"}"#.to_owned()).await;
+    assert_eq!(response.status(), StatusCode::UNPROCESSABLE_ENTITY);
+
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    let result: Value = serde_json::from_slice(&body).unwrap();
+    assert_eq!(result["message"], "Validation error");
+    assert_eq!(result["details"]["username"][0]["code"], "length");
+    assert_eq!(result["details"]["username"][0]["message"], Value::Null);
+    assert_eq!(
+        result["details"]["username"][0]["params"]["min"],
+        Value::Number(2.into())
+    )
+}
+
+pub(super) async fn test_get_users(app: Router) {
+    let response = make_get_request(app, "/users").await;
+    assert_eq!(response.status(), StatusCode::OK);
+
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    assert_eq!(&body[..], br#"{"users":[{"id":1,"username":"test"}]}"#);
+}