feat: complete task breakdown and checklist

- Generated comprehensive tasks.md with 16 major tasks and 94+ subtasks
- Created interactive CHECKLIST.md with progress tracking and dashboard
- Updated implementation plan with security-validated tech stack
- Added phase-by-phase breakdown with dependencies and success criteria
- Ready for Phase 0: Security Foundation & Environment Setup

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.specify/templates/plan-template.md

@@ -0,0 +1,14 @@
+# Implementation Plan Template
+
+## Context Analysis
+[To be filled by planning process]
+
+## Architecture Design  
+[To be filled by planning process]
+
+## Implementation Phases
+[To be filled by planning process]
+
+## Validation Gates
+[To be filled by planning process]
+