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/api/src/error/adapter.rs

@@ -0,0 +1,32 @@
+use axum::{extract::rejection::JsonRejection, http::StatusCode};
+use sea_orm::DbErr;
+
+use app::error::UserError;
+
+use super::traits::HTTPError;
+
+impl HTTPError for JsonRejection {
+    fn to_status_code(&self) -> StatusCode {
+        match self {
+            JsonRejection::JsonSyntaxError(_) => StatusCode::BAD_REQUEST,
+            _ => StatusCode::BAD_REQUEST,
+        }
+    }
+}
+
+impl HTTPError for DbErr {
+    fn to_status_code(&self) -> StatusCode {
+        match self {
+            DbErr::ConnectionAcquire(_) => StatusCode::INTERNAL_SERVER_ERROR,
+            _ => StatusCode::INTERNAL_SERVER_ERROR, // TODO:: more granularity
+        }
+    }
+}
+
+impl HTTPError for UserError {
+    fn to_status_code(&self) -> StatusCode {
+        match self {
+            UserError::NotFound => StatusCode::NOT_FOUND,
+        }
+    }
+}

thoughts-backend/api/src/error/core.rs

@@ -0,0 +1,10 @@
+pub struct ApiError(pub(super) anyhow::Error);
+
+impl<E> From<E> for ApiError
+where
+    E: Into<anyhow::Error>,
+{
+    fn from(err: E) -> Self {
+        Self(err.into())
+    }
+}

thoughts-backend/api/src/error/handler.rs

@@ -0,0 +1,36 @@
+use axum::{
+    extract::rejection::JsonRejection,
+    http::StatusCode,
+    response::{IntoResponse, Response},
+    Json,
+};
+use sea_orm::DbErr;
+
+use app::error::UserError;
+
+use super::{ApiError, HTTPError};
+use crate::models::ApiErrorResponse;
+
+impl IntoResponse for ApiError {
+    fn into_response(self) -> Response {
+        let err = self.0;
+
+        let (status, message) = if let Some(err) = err.downcast_ref::<DbErr>() {
+            tracing::error!(%err, "error from db:");
+            (err.to_status_code(), "DB error".to_string()) // hide the detail
+        } else if let Some(err) = err.downcast_ref::<UserError>() {
+            (err.to_status_code(), err.to_string())
+        } else if let Some(err) = err.downcast_ref::<JsonRejection>() {
+            tracing::error!(%err, "error from extractor:");
+            (err.to_status_code(), err.to_string())
+        } else {
+            tracing::error!(%err, "error from other source:");
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Unknown error".to_string(),
+            )
+        };
+
+        (status, Json(ApiErrorResponse { message })).into_response()
+    }
+}

thoughts-backend/api/src/error/mod.rs

@@ -0,0 +1,7 @@
+mod adapter;
+mod core;
+mod handler;
+mod traits;
+
+pub use core::ApiError;
+pub use traits::HTTPError;

thoughts-backend/api/src/error/traits.rs

@@ -0,0 +1,5 @@
+use axum::http::StatusCode;
+
+pub trait HTTPError {
+    fn to_status_code(&self) -> StatusCode;
+}