docs: Clean changelog of closed-source performance metrics

Removed:
- Factor count (closed)
- Strategy count (closed)
- Sharpe/return/drawdown numbers (closed)

Only open-source feature descriptions remain.

changelog/v2.0.0.md

@@ -2,7 +2,7 @@
 
 **Release Date:** 2026-04-10
 
-**Tag:** v2.0.0-2026.04.10
+**Tag:** v2.0.0
 
 ---
 
@@ -27,12 +27,12 @@ Major update adding AI-powered strategy generation, realistic backtesting, and c
 - **Forward-Fill Support**: Daily factors → 1-min frequency
 - **Proper Annualization**: sqrt(252*1440) for 1-min data
 
-### CLI Commands (6 New)
+### CLI Commands
+- `rdagent predix` - Show beautiful welcome screen (perfect for screenshots!)
 - `rdagent start_llama` - Start llama.cpp server
 - `rdagent start_loop` - Start strategy generator loop with auto-restart
 - `rdagent generate_strategies` - Generate strategies from factors
 - `rdagent optimize_portfolio` - Portfolio optimization
-- `rdagent strategies_report` - Generate performance reports
 - `rdagent eval_all` - Evaluate factors with full data
 - `rdagent batch_backtest` - Batch backtest existing factors
 - `rdagent report` - Generate PDF performance reports
@@ -45,20 +45,12 @@ Major update adding AI-powered strategy generation, realistic backtesting, and c
 
 ---
 
-## 📊 Performance
-
-- **2,800+ Factors**: Generated and evaluated
-- **14 Qualified Strategies**: After strict re-evaluation
-- **Top Strategy**: Sharpe 6.04, 21.88% annualized return, -1.57% max drawdown
-
----
-
 ## 🔧 Changed
 
 - Utility scripts organized in `scripts/` directory
 - Generated data moved to `results/`
 - Config files moved to `constraints/`
-- Root directory cleaned (872 → 29 files)
+- Root directory cleaned
 
 ---
 
@@ -81,6 +73,9 @@ pip install -e .
 ## 🚀 Quick Start
 
 ```bash
+# Show welcome screen
+rdagent predix
+
 # Start LLM server
 rdagent start_llama