feat(core): integrate GDB and TCP listener for reverse shells

This release introduces deep GDB integration and network listening
capabilities directly into the ExploitLab pipeline.

GDB Integration:
- Add `GDB.attach()` to hook mid-execution and `GDB.debug()` to spawn from scratch.
- Add module aliases (`attach`, `debug`) and export them to the global API.
- Implement auto-detection for graphical terminals and plugins (pwndbg, peda, gef).
- Add breakpoint API, custom script sourcing, and headless `send_command()` execution.
- Implement `with` block context managers for clean teardowns.

Listener Capabilities:
- Introduce `listen()` TCP tube to catch incoming connections.
- Ensure full API parity with `Process` and `Remote` (send, recv, recvuntil).
- Add `.interactive()` support on listeners for instant reverse shell dropping.