fix(hookify): Fix Python import errors in plugin hooks

[ajbmachon]

Summary

Fixes Python import errors (No module named 'hookify') in the hookify plugin when running in Claude Code's versioned plugin cache.

Problem

The hookify plugin's Python hooks fail to import core modules because:

1. Original code assumed: parent_dir/hookify/core/... exists
2. Claude Code's actual structure: .../cache/{marketplace}/{plugin}/{version}/core/...
3. CLAUDE_PLUGIN_ROOT points to the versioned directory (e.g., .../hookify/0.1.0/)
4. There's no nested hookify/ package inside - the code lives directly under the version directory

# Original (broken)
from hookify.core.config_loader import load_rules  # ❌ No 'hookify' package

# Fixed
from core.config_loader import load_rules  # ✅ Relative to PLUGIN_ROOT

Solution

1. Add hooks/common.py - Centralizes import logic with correct sys.path handling
2. Update all hook scripts - Import from common module (DRY principle)
3. Fix core/rule_engine.py - Use relative imports (.config_loader)

Changes

File	Change
hooks/common.py	New shared module for imports and utilities
hooks/*.py	Simplified to use common module
core/rule_engine.py	Changed to relative import

Testing

Verified imports work correctly:

CLAUDE_PLUGIN_ROOT=.../hookify/0.1.0 python3 -c "from common import load_rules; print('OK')"
# Output: OK

Test plan

• Install hookify plugin fresh
• Verify no import errors on tool use
• Test rule evaluation works correctly