Hook exit-code semantics are internally inconsistent: engine blocks on exit 1, docs/prompts teach exit 2

Files:

• code_puppy/hook_engine/executor.py:145 — blocked = exit_code == 1
• code_puppy/hook_engine/executor.py:1-13 (module docstring) — "Exit code 1 => block the operation; Exit code 2 => error feedback to Claude"
• code_puppy/mcp_prompts/hook_creator.py:36 — "PreToolUse - Before a tool executes (can block with exit code 2)"
• code_puppy/mcp_prompts/hook_creator.py:60-71 — example hook script uses exit 2 to "Block dangerous commands"
• code_puppy/plugins/claude_code_hooks/register_callbacks.py:85 — "exit 1 blocks and exit 2 routes stderr back as a tool error"

Severity: High (correctness)

The engine treats exit 1 as blocking. But the bundled hook-creation prompt (mcp_prompts/hook_creator.py) — the very documentation injected to teach users/LLMs how to write hooks — instructs them to exit 2 to block. A hook written by following that prompt will silently fail to block the dangerous operation it was written to prevent. That's the worst possible failure mode for a safety mechanism.

Note also that Claude Code's own documented convention is exit code 2 = blocking error (stderr fed to Claude), and any non-zero other code = non-blocking error. Since this engine explicitly advertises "Claude Code Hook Compatibility" (executor.py docstring), hooks ported from Claude Code (exit 2 to block) will not block here either.

Suggested fix: Pick one convention (recommend matching Claude Code: exit_code == 2 blocks) and align all three places — executor.py logic + docstring, hook_creator.py prompt, and claude_code_hooks plugin docs. Add a regression test asserting the blocking exit code matches the documented one.

Filed by Zen Reviewer B (code-puppy-60635a)

Start by comparing the exit-code logic and documentation in code_puppy/hook_engine/executor.py, mcp_prompts/hook_creator.py, and plugins/claude_code_hooks/register_callbacks.py. Trace the existing hook execution path, then add a regression test that verifies the documented blocking code is enforced and confirm all three locations describe the same behavior.