feat: add codemcp run command to CLI

[ezyang]

Stack from ghstack (oldest at bottom):

• -> feat: add codemcp run command to CLI #271

Add a codemcp run COMMAND to the cli which runs the command as defined in codemcp.toml the same way the RunCommand tool does it. However, do NOT reuse RunCommand's code (which is tuned for MCP usage), instead reimplement the subprocess call code correctly. stdin/stdout/stderr should be inherited. Do NOT do git commits. Just run the command.

292b66b  (Base revision)
0015442  Add 'run' command to CLI to execute commands from codemcp.toml without git commits
adba9fb  Add end-to-end tests for the new 'run' command
375e216  Auto-commit format changes
ed25816  Auto-commit lint changes
d536fef  Add sys import to test_run_command.py
4daf9cb  Update test_run_command_exists to use sys.executable
7e2369e  Update test_run_command_basic to use sys.executable
41ff40d  Update test_run_command_with_args to use sys.executable
83691fe  Update test_run_command_error_exit_code to use sys.executable
189dcdf  Update test_run_command_missing_command to use sys.executable
6f476f5  Return non-zero exit code when command is not found in codemcp.toml
HEAD     Return non-zero exit code for invalid command configuration

codemcp-id: 278-feat-add-codemcp-run-command-to-cli