Pivot: CLI hook scaffold replacing MCP server

[ProduktEntdecker]

Overview

PatchPilot is pivoting from an MCP server to a Claude Code pre-execution hook.

Why

• MCP requires manual invocation (user must ask)
• Hook is automatic (intercepts before execution)
• Simpler installation (single settings.json entry)
• Global protection across all chats

Acceptance Criteria

• Remove MCP server code from src/index.ts
• Create new CLI entry point that reads JSON from stdin
• Parse hook input structure (tool_name, tool_input.command, etc.)
• Output valid hook response JSON to stdout
• Exit code 0 for allow, exit code 2 for block (fallback)
• Update package.json bin entry

Hook Input Format

{
  "hook_event_name": "PreToolUse",
  "tool_name": "Bash",
  "tool_input": {
    "command": "npm install lodash@4.17.0"
  }
}

Hook Output Format

{
  "hookSpecificOutput": {
    "hookEventName": "PreToolUse",
    "permissionDecision": "allow" | "deny" | "ask",
    "permissionDecisionReason": "..."
  }
}

Priority: P0 (blocks all other work)