Add merge-plans-with-file and quick-plan-with-file prompts for enhanced planning workflows

- Introduced merge-plans-with-file prompt for aggregating multiple planning artifacts, resolving conflicts, and synthesizing a unified execution plan.
- Implemented detailed execution process including discovery, normalization, conflict detection, resolution, and synthesis phases.
- Added quick-plan-with-file prompt for rapid planning with minimal documentation, utilizing multi-agent analysis for actionable outputs.
- Both prompts support various input formats and provide structured outputs for execution and documentation.

Author: catlog22