Link support codes to agent sessions

- Server: Accept support_code param in WebSocket connection
- Server: Link code to session when agent connects, mark as connected
- Server: Mark code as completed when agent disconnects
- Agent: Accept support code from command line argument
- Agent: Send hostname and support_code in WebSocket params
- Portal: Trigger agent download with code in filename
- Portal: Show code reminder in download instructions
- Dashboard: Add machines list fetching (Access tab)
- Add TODO.md for feature tracking

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/src/support_codes.rs

@@ -147,6 +147,27 @@ impl SupportCodeManager {
         }
     }
 
+    /// Link a support code to an actual WebSocket session
+    pub async fn link_session(&self, code: &str, real_session_id: Uuid) {
+        let mut codes = self.codes.write().await;
+        if let Some(support_code) = codes.get_mut(code) {
+            // Update session_to_code mapping with real session ID
+            let old_session_id = support_code.session_id;
+            support_code.session_id = real_session_id;
+
+            // Update the reverse mapping
+            let mut session_to_code = self.session_to_code.write().await;
+            session_to_code.remove(&old_session_id);
+            session_to_code.insert(real_session_id, code.to_string());
+        }
+    }
+
+    /// Get code by its code string
+    pub async fn get_code(&self, code: &str) -> Option<SupportCode> {
+        let codes = self.codes.read().await;
+        codes.get(code).cloned()
+    }
+
     /// Mark a code as completed
     pub async fn mark_completed(&self, code: &str) {
         let mut codes = self.codes.write().await;