feat: implement friends API with routes to get friends list and update thought visibility logic

thoughts-backend/api/src/routers/friends.rs

@@ -0,0 +1,24 @@
+use crate::{error::ApiError, extractor::AuthUser};
+use app::{persistence::user, state::AppState};
+use axum::{extract::State, response::IntoResponse, routing::get, Json, Router};
+use models::schemas::user::UserListSchema;
+
+#[utoipa::path(
+    get,
+    path = "",
+    responses(
+        (status = 200, description = "List of authenticated user's friends", body = UserListSchema)
+    ),
+    security(("bearer_auth" = []))
+)]
+async fn get_friends_list(
+    State(state): State<AppState>,
+    auth_user: AuthUser,
+) -> Result<impl IntoResponse, ApiError> {
+    let friends = user::get_friends(&state.conn, auth_user.id).await?;
+    Ok(Json(UserListSchema::from(friends)))
+}
+
+pub fn create_friends_router() -> Router<AppState> {
+    Router::new().route("/", get(get_friends_list))
+}