Feature Request: Diff-based output for repeated command responses

When running commands that produce repetitive or lengthy output across multiple runs (e.g., make, npm install, pip install), it would be very useful if RTK could send only the diff between the current and previous response instead of the full log every time.

This would significantly reduce noise and make it easier to spot changes between runs — particularly useful in iterative build/install workflows.

Proposed behavior:

• By default, show only the diff when the same command is re-run and a previous response exists
• Add a flag (e.g., --full-log or --no-diff) to override this and send the complete output

Use cases:

• Incremental builds (make, cmake --build)
• Dependency installs (npm install, pip install, cargo build)
• Any long-running command where output is mostly stable between runs