hookify plugin: support global rules from ~/.claude/

Feature Request

The hookify plugin currently only loads rules from the project-local .claude/hookify.*.local.md directory. It would be useful to also load rules from ~/.claude/hookify.*.local.md for cross-repo concerns.

Use Case

Rules like "remind me to use TDD when creating new production source files" apply to every repository, not just one. Currently you need to duplicate the rule file into every project's .claude/ directory.

Proposed Change

In core/config_loader.py, load_rules() should also glob ~/.claude/hookify.*.local.md:

# Project-local rules
pattern = os.path.join('.claude', 'hookify.*.local.md')
files = glob.glob(pattern)

# Global rules from ~/.claude/
global_pattern = os.path.join(os.path.expanduser('~'), '.claude', 'hookify.*.local.md')
files += glob.glob(global_pattern)

Project-local rules could take precedence over global rules with the same name (allowing per-project overrides).

Workaround

I've applied this as a local edit to the installed plugin, but it'll be overwritten on plugin updates.