feat(tui): add usage overlay and sidebar for displaying usage statistics and tasks

feat(tui): implement status bar with connection and turn state indicators
feat(tui): create workflow panel for agent status and progress visualization
feat(web): introduce web frontend interface with static file serving
feat(ws): add WebSocket interface for real-time communication and session management

apps/interfaces/grpc/src/lib.rs

@@ -0,0 +1,58 @@
+//! gRPC interface — high-performance RPC with protobuf.
+//!
+//! Uses tonic + prost for gRPC code generation. To enable:
+//! 1. Add `tonic` and `prost` to Cargo.toml
+//! 2. Create proto/ directory with service definitions
+//! 3. Generate code via build.rs
+//! 4. Implement the generated service traits
+//!
+//! Example service:
+//! ```protobuf
+//! service Zesdex {
+//!   rpc Chat(ChatRequest) returns (ChatResponse);
+//!   rpc ListSessions(ListSessionsRequest) returns (ListSessionsResponse);
+//!   rpc StreamChat(ChatRequest) returns (stream ChatResponse);
+//! }
+//! ```
+//!
+//! For now, this crate provides a minimal HTTP health-check endpoint
+//! so consumers can verify the gRPC server is reachable.
+
+use axum::routing::get;
+use axum::Router;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use tracing::info;
+
+/// gRPC server state (minimal for health checks).
+pub struct GrpcState {
+    pub version: String,
+}
+
+/// Build the gRPC server router.
+pub fn build_router(state: Arc<GrpcState>) -> Router {
+    Router::new()
+        .route("/grpc/health", get(health_check))
+        .with_state(state)
+}
+
+/// Health check endpoint.
+async fn health_check(
+    axum::extract::State(_state): axum::extract::State<Arc<GrpcState>>,
+) -> &'static str {
+    "gRPC server is running"
+}
+
+/// Run the gRPC server (currently HTTP health only; replace with tonic when ready).
+pub async fn run_server(port: u16) -> anyhow::Result<()> {
+    let state = Arc::new(GrpcState {
+        version: env!("CARGO_PKG_VERSION").to_string(),
+    });
+    let app = build_router(state);
+    let addr = SocketAddr::from(([0, 0, 0, 0], port));
+    info!("gRPC server listening on {addr}");
+    info!("Note: gRPC currently runs HTTP health endpoint. Add tonic+prost for full gRPC.");
+    let listener = tokio::net::TcpListener::bind(addr).await?;
+    axum::serve(listener, app).await?;
+    Ok(())
+}