Update documentation to clarify GPU control commands

- Revised README, architecture, CLI, and other documentation to specify that both `Ctrl+C` and `Ctrl+D` now stop the GPU while preserving disk data, correcting previous inaccuracies.
- Enhanced access card and setup instructions to reflect the updated command behavior for better user understanding.
- Updated tests to ensure the new command behaviors are validated and documented correctly, improving overall clarity in GPU management.

src/gpu_rent/setup_wizard.py

@@ -99,7 +99,7 @@ def run_setup(
 
     do_wd = install_watchdog
     if do_wd is None and confirm:
-        do_wd = confirm("Установить local-watchdog (аварийный stop без Ctrl+C)?")
+        do_wd = confirm("Установить local-watchdog (аварийный stop, если процесс умер)?")
     if do_wd:
         from gpu_rent.local_watchdog import install_watchdog as _install