feat: migrate imphnen-backend-hackathon into workspace as imphnen-hackathon crate

Consolidates the standalone hackathon backend (16 crates) into a single
imphnen-hackathon crate following the existing clean architecture patterns.
All endpoints are exposed under /v1/hackathon/ via the gateway.

Features migrated:
- Auth: Supabase-based signup/login/GitHub OAuth/password reset (own JWT)
- Users: profile management with team listing
- Teams: CRUD with city validation, deadline enforcement, invite system
- Invitations: team member invitations with accept/reject flow
- Join Requests: team join request workflow
- Chat: team messaging with author/leader delete permissions
- Submissions: project submission lifecycle (draft→pending→submitted)
- Storage: Supabase Storage file upload endpoints
- Certificates: public user certificate data endpoint
- Winners: public winners listing
- Admin: admin-only CRUD for all entities

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

imphnen-hackathon/src/chat/infrastructure/http/dto.rs

@@ -0,0 +1,43 @@
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+use uuid::Uuid;
+use chrono::{DateTime, Utc};
+use crate::chat::domain::entity::*;
+
+#[derive(Debug, Serialize, Deserialize, ToSchema)]
+pub struct MessageResponse {
+    pub id: Uuid,
+    pub team_id: Uuid,
+    pub user_id: Uuid,
+    pub user_fullname: String,
+    pub user_avatar: Option<String>,
+    pub message: String,
+    pub created_at: Option<DateTime<Utc>>,
+    pub updated_at: Option<DateTime<Utc>>,
+}
+
+impl From<MessageWithUser> for MessageResponse {
+    fn from(e: MessageWithUser) -> Self {
+        Self {
+            id: e.id,
+            team_id: e.team_id,
+            user_id: e.user_id,
+            user_fullname: e.user_fullname,
+            user_avatar: e.user_avatar,
+            message: e.message,
+            created_at: e.created_at,
+            updated_at: e.updated_at,
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize, ToSchema)]
+pub struct SendMessageRequest {
+    pub message: String,
+}
+
+impl From<SendMessageRequest> for SendMessageInput {
+    fn from(r: SendMessageRequest) -> Self {
+        Self { message: r.message }
+    }
+}

imphnen-hackathon/src/chat/infrastructure/http/handlers.rs

@@ -0,0 +1,36 @@
+use axum::{Extension, Json, extract::Path, response::IntoResponse};
+use std::sync::Arc;
+use uuid::Uuid;
+use imphnen_utils::{errors::AppError, response_format::{ApiSuccess, ApiMessage}};
+use crate::middleware::hackathon_auth::HackathonAuthUser;
+use crate::chat::domain::service::ChatService;
+use super::dto::*;
+
+pub async fn get_team_messages_handler(
+    Extension(service): Extension<Arc<dyn ChatService>>,
+    Extension(auth): Extension<HackathonAuthUser>,
+    Path(team_id): Path<Uuid>,
+) -> Result<axum::response::Response, AppError> {
+    let messages = service.get_team_messages(team_id, auth.user_id).await?;
+    let response: Vec<MessageResponse> = messages.into_iter().map(MessageResponse::from).collect();
+    Ok(ApiSuccess(response).into_response())
+}
+
+pub async fn send_message_handler(
+    Extension(service): Extension<Arc<dyn ChatService>>,
+    Extension(auth): Extension<HackathonAuthUser>,
+    Path(team_id): Path<Uuid>,
+    Json(body): Json<SendMessageRequest>,
+) -> Result<axum::response::Response, AppError> {
+    let message = service.send_message(team_id, auth.user_id, body.into()).await?;
+    Ok(ApiSuccess(MessageResponse::from(message)).into_response())
+}
+
+pub async fn delete_message_handler(
+    Extension(service): Extension<Arc<dyn ChatService>>,
+    Extension(auth): Extension<HackathonAuthUser>,
+    Path(message_id): Path<Uuid>,
+) -> Result<axum::response::Response, AppError> {
+    service.delete_message(message_id, auth.user_id).await?;
+    Ok(ApiMessage::ok("Message deleted").into_response())
+}

imphnen-hackathon/src/chat/infrastructure/http/mod.rs

@@ -0,0 +1,3 @@
+pub mod dto;
+pub mod handlers;
+pub mod routes;

imphnen-hackathon/src/chat/infrastructure/http/routes.rs

@@ -0,0 +1,22 @@
+use axum::{middleware::from_fn, routing::{delete, get, post}, Extension, Router};
+use sqlx::PgPool;
+use std::sync::Arc;
+use crate::chat::application::chat_service::ChatServiceImpl;
+use crate::chat::domain::service::ChatService;
+use crate::chat::infrastructure::persistence::PostgresChatRepository;
+use crate::common::hackathon_jwt::HackathonJwtService;
+use crate::middleware::hackathon_auth::hackathon_auth_middleware;
+use super::handlers::*;
+
+pub fn build_chat_routes(pool: Arc<PgPool>, jwt: Arc<HackathonJwtService>) -> Router {
+    let service: Arc<dyn ChatService> = Arc::new(ChatServiceImpl::new(
+        Arc::new(PostgresChatRepository::new(pool.clone())),
+    ));
+    Router::new()
+        .route("/chat/teams/:team_id", get(get_team_messages_handler).post(send_message_handler))
+        .route("/chat/messages/:message_id", delete(delete_message_handler))
+        .layer(Extension(service))
+        .layer(Extension(jwt.clone()))
+        .layer(Extension(pool))
+        .layer(from_fn(hackathon_auth_middleware))
+}