feat: Add multi-host config and dynamic project scanning

Backend:
- Load hosts from config/hosts.json
- New /api/hosts endpoint listing available hosts
- Dynamic project scanning with configurable depth
- Support for local and SSH hosts (SSH execution coming next)

Frontend (by Web-UI Claude):
- Slash commands: /clear, /help, /export, /scroll, /new, /info
- Chat export as Markdown

Config:
- hosts.json defines hosts with connection info and base paths
- hosts.example.json as template (real config is gitignored)
- Each host has name, description, color, icon, basePaths

Next steps:
- SSH command execution for remote hosts
- Frontend host selector UI
- Multi-agent collaboration

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

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

frontend/src/hooks/useClaudeSession.js

@@ -295,6 +295,7 @@ export function useClaudeSession() {
     sendMessage,
     stopSession,
     clearMessages,
-    setError
+    setError,
+    setMessages
   };
 }