fix(commands): replace inline !` command syntax with explicit Bash blocks

[tyoon10]

Closes #600.

Summary

status.md, transfer.md, cancel.md, and result.md used the inline !node "..." "$ARGUMENTS" shorthand that is not supported by the runtime parsing. This replaces it with an explicit Bash(node:*) code block (already allowed by frontmatter) followed by post-processing instructions, matching the pattern already used in review.md.

- !`node "${CLAUDE_PLUGIN_ROOT}/scripts/codex-companion.mjs" status "$ARGUMENTS"`
+ ```bash
+ node "${CLAUDE_PLUGIN_ROOT}/scripts/codex-companion.mjs" status "$ARGUMENTS"
+ ```

No runtime behavior changes; the same command is executed. node --test tests/commands.test.mjs passes.