docs: add v0.5.0 roadmap for performance metrics and status APIs

Added new pre-v1.0 release (v0.5.0) with two new API endpoints:

1. Performance Metrics API (GET /metrics/performance)
   - Query model performance over custom date ranges
   - Returns total return, trade count, win rate, daily P&L stats
   - Enables model comparison and strategy evaluation

2. Status & Coverage Endpoint (GET /status)
   - Comprehensive system status in single endpoint
   - Price data coverage (symbols, date ranges, gaps)
   - Model simulation progress (date ranges, completion %)
   - System health (database, MCP services, disk usage)

Updated version history:
- Added v0.4.0 (current release)
- Added v0.5.0 (planned)
- Renamed v1.3.0 to "Advanced performance metrics"

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

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

ROADMAP.md

@@ -679,11 +679,13 @@ To propose a new feature:
 
 - **v0.1.0** - Initial release with batch execution
 - **v0.2.0** - Docker deployment support
-- **v0.3.0** - REST API, on-demand downloads, database storage (current)
+- **v0.3.0** - REST API, on-demand downloads, database storage
+- **v0.4.0** - Daily P&L calculation, day-centric results API, reasoning summaries (current)
+- **v0.5.0** - Performance metrics & status APIs (planned)
 - **v1.0.0** - Production stability & validation (planned)
 - **v1.1.0** - API authentication & security (planned)
 - **v1.2.0** - Position history & analytics (planned)
-- **v1.3.0** - Performance metrics & analytics (planned)
+- **v1.3.0** - Advanced performance metrics & analytics (planned)
 - **v1.4.0** - Data management API (planned)
 - **v1.5.0** - Web dashboard UI (planned)
 - **v1.6.0** - Advanced configuration & customization (planned)
@@ -691,4 +693,4 @@ To propose a new feature:
 
 ---
 
-Last updated: 2025-11-01
+Last updated: 2025-11-06