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/application/src/ports/token.rs

@@ -0,0 +1,26 @@
+//! TokenService port — JWT access and refresh token abstraction.
+//!
+//! Defines the trait that JWT adapter implementations provide. Covers
+//! token generation (pair of access + refresh tokens) and access token
+//! verification (returns the subject claim).
+
+use anyhow::Result;
+
+/// Abstraction for JWT-based token generation and verification.
+///
+/// Implementors handle signing key management, token serialisation,
+/// and expiry validation. The trait is `Send + Sync` for use across
+/// thread boundaries.
+pub trait TokenService: Send + Sync {
+    /// Generate an access + refresh token pair for the given subject
+    /// identifier.
+    ///
+    /// Returns `(access_token, refresh_token)`.
+    fn generate_tokens(&self, sub: &str) -> Result<(String, String)>;
+
+    /// Verify an access token and return the embedded subject claim.
+    ///
+    /// Returns `Err` if the token is expired, malformed, or has an
+    /// invalid signature.
+    fn verify_access_token(&self, token: &str) -> Result<String>;
+}