Add deepwork rules clear_queue command for queue management

[nhorton]

Summary

Introduces a new CLI command deepwork rules clear_queue to replace manual file deletion commands for clearing the rules queue. This improves usability and provides a cleaner interface for queue management.

Changes

• New CLI command: Added deepwork rules clear_queue subcommand under a new rules command group

  • Clears all JSON entries from .deepwork/tmp/rules/queue/
  • Provides user-friendly feedback (shows count of cleared entries or "already empty" message)
  • Implemented in new src/deepwork/cli/rules.py module

• Updated documentation: Replaced all instances of manual queue clearing commands

  • Changed rm -rf .deepwork/tmp/rules/queue/*.json to deepwork rules clear_queue in:
    • .claude/settings.json (deepwork_rules.define hook)
    • .deepwork/jobs/manual_tests/steps/run_fire_tests.md
    • .deepwork/jobs/manual_tests/steps/run_not_fire_tests.md
  • Updated explanatory comments to reference the new command

• CLI integration: Registered new rules command group in main CLI entry point

Implementation Details

• Uses existing RulesQueue class from deepwork.core.rules_queue for queue operations
• Provides colored console output using Rich library for better UX
• Returns count of cleared entries for transparency
• Handles empty queue gracefully with appropriate messaging