chore: Add E2E test helper scripts and API key management

Added helper scripts to make running E2E tests easier:

1. .env.example - Template for API key storage
2. run_e2e_with_env.py - Loads API key from .env and runs E2E test
3. monitor_e2e.py - Real-time monitoring script for live output
4. run_e2e_test.bat - Windows batch script for easy execution

These scripts make it easy to:
- Store API key securely in .env (already in .gitignore)
- Run E2E test without manually setting environment variables
- Monitor test progress in real-time

Usage:
  python run_e2e_with_env.py  # Background execution
  python monitor_e2e.py       # Live output in terminal

API key is stored in .env (not committed to git) and automatically
loaded by helper scripts.

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

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

run_e2e_with_env.py

@@ -0,0 +1,43 @@
+"""
+Helper script to run E2E test with API key from .env file
+
+This script loads the ANTHROPIC_API_KEY from .env and runs the E2E test.
+"""
+import os
+import sys
+import subprocess
+from pathlib import Path
+
+# Load .env file
+env_file = Path(__file__).parent / ".env"
+
+if env_file.exists():
+    print("Loading API key from .env file...")
+    with open(env_file) as f:
+        for line in f:
+            line = line.strip()
+            if line and not line.startswith('#') and '=' in line:
+                key, value = line.split('=', 1)
+                os.environ[key.strip()] = value.strip()
+
+    if 'ANTHROPIC_API_KEY' in os.environ:
+        print(f"[OK] API key loaded: {os.environ['ANTHROPIC_API_KEY'][:20]}...")
+    else:
+        print("[FAIL] No ANTHROPIC_API_KEY found in .env")
+        sys.exit(1)
+else:
+    print(f"[FAIL] .env file not found at {env_file}")
+    print("\nPlease create a .env file with your API key:")
+    print("ANTHROPIC_API_KEY=your-key-here")
+    sys.exit(1)
+
+# Run the E2E test
+print("\nRunning E2E test...")
+print("=" * 80)
+print()
+
+python_exe = "c:/Users/antoi/anaconda3/envs/test_env/python.exe"
+test_script = Path(__file__).parent / "tests" / "test_phase_3_2_e2e.py"
+
+result = subprocess.run([python_exe, str(test_script)])
+sys.exit(result.returncode)