feat: Install/bind `dxon` inside containers and allow it to communicate with the host runtime.

[PriyanshuPz]

TODO

• Host runs a small socket server at $DXON_DIR/dxon.sock
• Socket is bind-mounted into containers at /run/dxon.sock
• dxon inside container acts as a thin client
• Commands like dxon open . inside container send requests to host
• Host translates container path → host path and performs action (e.g. open editor)

Benefits:

• Allows dxon open . from inside container
• Cleaner UX for multi-project containers
• Enables future commands (dxon logs, dxon restart, dxon exec, etc.)

Possible implementation approach:

• detect container mode using /run/dxon.sock
• send JSON RPC over unix socket
• host handles editor launch and other host-only actions