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/domain/src/auth/session_id.rs

@@ -0,0 +1,106 @@
+//! Validated session identifier newtype.
+//!
+//! [`SessionId`] wraps a `String` that has been checked for path-traversal
+//! characters. Construction via `SessionId::new(str)` validates the input
+//! once; the guarantee is then enforced by the type system for all
+//! downstream use.
+//!
+//! # Validation rules
+//!
+//! - Must not be empty
+//! - Must only contain alphanumeric characters, hyphens, and underscores
+
+use serde::{Deserialize, Serialize};
+use std::fmt;
+use std::path::Path;
+use std::path::PathBuf;
+
+/// A validated session identifier.
+///
+/// Guarantees the inner string is non-empty and contains no path-traversal
+/// characters (`/`, `\\`, `..`) or other unsafe delimiters.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
+pub struct SessionId(String);
+
+impl SessionId {
+    /// Validate and construct a `SessionId`.
+    ///
+    /// Returns `Err(msg)` if the input contains path separators, `..`, or
+    /// is empty.
+    pub fn new(id: &str) -> Result<Self, String> {
+        if id.is_empty() {
+            return Err("session id must not be empty".to_string());
+        }
+        if id.contains('/') || id.contains('\\') || id.contains("..") {
+            return Err(format!(
+                "session id '{id}' must not contain path separators"
+            ));
+        }
+        Ok(SessionId(id.to_string()))
+    }
+
+    /// Return the underlying string.
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+
+    /// Return the underlying owned string.
+    pub fn into_string(self) -> String {
+        self.0
+    }
+
+    /// Append this session id as a component of `base_dir`, yielding
+    /// `base_dir / self.0`.
+    ///
+    /// Safe because the id has been validated to contain no path separators.
+    pub fn join_to(&self, base_dir: &Path) -> PathBuf {
+        base_dir.join(&self.0)
+    }
+}
+
+impl AsRef<str> for SessionId {
+    fn as_ref(&self) -> &str {
+        &self.0
+    }
+}
+
+impl fmt::Display for SessionId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl From<SessionId> for String {
+    fn from(sid: SessionId) -> Self {
+        sid.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_valid_uuids() {
+        assert!(SessionId::new("550e8400-e29b-41d4-a716-446655440000").is_ok());
+        assert!(SessionId::new("my-session_123").is_ok());
+    }
+
+    #[test]
+    fn test_rejects_path_traversal() {
+        assert!(SessionId::new("../etc/passwd").is_err());
+        assert!(SessionId::new("foo/../../bar").is_err());
+        assert!(SessionId::new("foo\\..\\bar").is_err());
+    }
+
+    #[test]
+    fn test_rejects_empty() {
+        assert!(SessionId::new("").is_err());
+    }
+
+    #[test]
+    fn test_into_string() {
+        let sid = SessionId::new("abc-123").unwrap();
+        assert_eq!(sid.into_string(), "abc-123");
+    }
+}