Operate DuckStation

Resolve the exact emulator build, media/executable revision and requested guest checkpoint. Preserve an unchanged baseline and use an isolated data tree with copied fixtures and saves. Verify the resolved paths rather than assuming a changed working directory isolates the installation.

Read only the relevant reference:

• Commands and isolation: launches, executable overrides, state files and the non-executing command builder.
• Debugging and evidence: guest/host address domains, symbols, GDB, PCDrv, logs and GPU replay.
• Textures and patches: dump identities, replacement matching, cheat state and disc patches.

The command builder prints POSIX shell text and never launches. Use argument arrays for execution. Do not equate generating a command with permission to run or mutate user state.