fix(ci): Fix GitLab CI YAML syntax and PPOConfig compilation errors

Two critical fixes for successful pipeline execution:

1. GitLab CI YAML Syntax Fix (.gitlab-ci.yml:84-86)
   - Wrapped echo commands containing colons in single quotes
   - Root cause: YAML parser interprets `"text: value"` as key-value pairs
   - Solution: Single quotes force literal string interpretation
   - Impact: Enables Docker build pipeline execution

2. Trading Service Compilation Fix (trading_service/src/services/enhanced_ml.rs:1328-1348)
   - Added missing early stopping fields to PPOConfig initialization
   - Fields: early_stopping_enabled, early_stopping_patience, early_stopping_min_delta, early_stopping_min_epochs
   - Values: Disabled by default for paper trading (early_stopping_enabled: false)
   - Impact: Resolves pre-push hook compilation error

Technical Details:
- YAML Issue: Colons followed by spaces trigger mapping syntax parsing
- Single quotes preserve shell variable expansion while forcing literal YAML strings
- Early stopping config matches PPOConfig struct updates from Wave D
- Default values: patience=5, min_delta=0.001, min_epochs=10

Validated:
- ✅ YAML syntax validated with PyYAML
- ✅ trading_service compilation successful (cargo check)
- ✅ Ready for GitLab CI/CD pipeline execution

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

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

scripts/validate_ppo_adapter.sh

@@ -0,0 +1,100 @@
+#!/bin/bash
+# PPO Adapter Validation Script
+# Date: 2025-10-30
+# Purpose: Verify PPO adapter meets production requirements
+
+set -e
+
+echo "========================================"
+echo "PPO ADAPTER VALIDATION SCRIPT"
+echo "========================================"
+echo ""
+
+PASS=0
+FAIL=0
+
+# Test 1: Check for synthetic data generation
+echo "Test 1: Checking for synthetic data generation..."
+if grep -q "generate_synthetic_trajectories" /home/jgrusewski/Work/foxhunt/ml/src/hyperopt/adapters/ppo.rs; then
+    echo "❌ FAIL: generate_synthetic_trajectories() found in ppo.rs"
+    FAIL=$((FAIL + 1))
+else
+    echo "✅ PASS: No synthetic data generation found"
+    PASS=$((PASS + 1))
+fi
+echo ""
+
+# Test 2: Check for data loading field
+echo "Test 2: Checking for dbn_data_dir field..."
+if grep -q "dbn_data_dir" /home/jgrusewski/Work/foxhunt/ml/src/hyperopt/adapters/ppo.rs; then
+    echo "✅ PASS: dbn_data_dir field found"
+    PASS=$((PASS + 1))
+else
+    echo "❌ FAIL: dbn_data_dir field NOT found"
+    FAIL=$((FAIL + 1))
+fi
+echo ""
+
+# Test 3: Check for early stopping config in PPOConfig
+echo "Test 3: Checking for early stopping config..."
+if grep -q "early_stopping_enabled" /home/jgrusewski/Work/foxhunt/ml/src/ppo/ppo.rs; then
+    echo "✅ PASS: early_stopping_enabled found in PPOConfig"
+    PASS=$((PASS + 1))
+else
+    echo "❌ FAIL: early_stopping_enabled NOT found in PPOConfig"
+    FAIL=$((FAIL + 1))
+fi
+echo ""
+
+# Test 4: Run unit tests
+echo "Test 4: Running unit tests..."
+if cargo test -p ml --lib hyperopt::adapters::ppo 2>&1 | grep -q "test result: ok"; then
+    echo "✅ PASS: Unit tests passed"
+    PASS=$((PASS + 1))
+else
+    echo "❌ FAIL: Unit tests failed"
+    FAIL=$((FAIL + 1))
+fi
+echo ""
+
+# Test 5: Check if integration tests compile
+echo "Test 5: Checking integration test compilation..."
+if cargo test -p ml --test hyperopt_ppo_real_data_test --no-run 2>&1 | grep -q "Finished"; then
+    echo "✅ PASS: Integration tests compile"
+    PASS=$((PASS + 1))
+else
+    echo "❌ FAIL: Integration tests don't compile"
+    FAIL=$((FAIL + 1))
+fi
+echo ""
+
+# Test 6: Check for EarlyStoppingObserver usage
+echo "Test 6: Checking for EarlyStoppingObserver integration..."
+if grep -q "EarlyStoppingObserver" /home/jgrusewski/Work/foxhunt/ml/src/hyperopt/adapters/ppo.rs; then
+    echo "✅ PASS: EarlyStoppingObserver used in adapter"
+    PASS=$((PASS + 1))
+else
+    echo "❌ FAIL: EarlyStoppingObserver NOT used in adapter"
+    FAIL=$((FAIL + 1))
+fi
+echo ""
+
+# Summary
+echo "========================================"
+echo "VALIDATION SUMMARY"
+echo "========================================"
+echo "Tests Passed: $PASS/6"
+echo "Tests Failed: $FAIL/6"
+echo ""
+
+if [ $FAIL -eq 0 ]; then
+    echo "✅ ALL TESTS PASSED - PPO ADAPTER READY FOR DEPLOYMENT"
+    exit 0
+else
+    echo "❌ VALIDATION FAILED - DO NOT DEPLOY PPO ADAPTER"
+    echo ""
+    echo "See reports for detailed fix instructions:"
+    echo "  - PPO_ADAPTER_VALIDATION_REPORT.md"
+    echo "  - PPO_ADAPTER_VALIDATION_SUMMARY.md"
+    exit 1
+fi