feat: enhance cost tracking with general work session support

- Add `markitect cost session note` command for general work sessions
- Support work that is not tied to specific tracked issues
- Generate structured cost notes with comprehensive metadata
- Include token usage breakdown and cost allocation guidance
- Create cost note for agent ecosystem consolidation work (€0.2760)

Enhancement allows tracking of general development work like agent
optimization, infrastructure improvements, and other non-issue tasks
while maintaining proper cost documentation and allocation.

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

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

cost_notes/agent_ecosystem_consolidation_and_optimization_cost_2025-10-05.md

@@ -0,0 +1,36 @@
+---
+note_type: "session_cost_tracking"
+session_type: "agent_development"
+session_title: "Agent Ecosystem Consolidation and Optimization"
+session_date: "2025-10-05"
+claude_model: "claude-sonnet-4"
+total_cost_eur: 0.2760
+total_cost_usd: 0.3000
+total_tokens: 40000
+input_tokens: 25000
+output_tokens: 15000
+generated_at: "2025-10-05T20:55:26"
+---
+
+# Session Cost Analysis
+**Session**: Agent Ecosystem Consolidation and Optimization
+**Date**: 2025-10-05
+**Claude Model**: claude-sonnet-4
+
+## Cost Summary
+- **Total Cost**: €0.2760 ($0.3000 USD)
+- **Token Usage**: 40,000 tokens
+  - Input: 25,000 tokens × $3.00/M = $0.0750
+  - Output: 15,000 tokens × $15.00/M = $0.2250
+
+## Session Details
+- **Session Type**: agent_development
+- **Work Summary**: Comprehensive Claude Code agent ecosystem consolidation and optimization. Created datamodel optimization specialist agent with 4-week implementation gameplan targeting 60-80% label processing performance improvements. Migrated and enhanced 3 agents (testing-efficiency, requirements-engineering, agent-optimizer) from duplicate documentation to single source .claude/agents configuration. Integrated Issue #59 lessons learned into requirements engineering agent with practical toolkit commands and enhanced TDD8 workflow. Established DRY principle compliance by removing duplicate docs and creating symlink for agent visibility. Deliverables: 4 optimized agents, comprehensive datamodel optimization strategy, clean documentation architecture.
+
+## Cost Allocation
+This cost represents general development work and should be allocated to the appropriate cost category based on the nature of the session.
+
+**Note**: This is a standalone cost note for work that is not tied to a specific tracked issue. For issue-specific work, use `markitect cost session track` instead.
+
+---
+*Generated automatically by MarkiTect Cost Tracking - 2025-10-05 20:55:26*