🧪 feat: complete BDD implementation with comprehensive documentation

Finalize BDD testing framework with:
- Unified step definitions using StepContext struct
- Proper server verification in theServerIsRunning step
- Robust JSON response handling with escaping and newline trimming
- Updated documentation reflecting current implementation
- Test validation script to ensure test quality
- All tests passing with proper black box testing

Key files updated:
- pkg/bdd/steps/steps.go: Unified step definitions
- pkg/bdd/testserver/client.go: Robust response validation
- pkg/bdd/README.md: Godog pattern guide
- doc/BDD_GUIDE.md: Updated usage guide
- adr/0008-bdd-testing.md: Updated ADR with current approach
- scripts/run-bdd-tests.sh: Test validation script

The BDD framework is now production-ready with comprehensive
documentation and proper testing practices.

scripts/run-bdd-tests.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+# BDD Test Runner Script
+# Runs all BDD tests and fails if there are undefined, pending, or skipped steps
+
+set -e
+
+echo "🧪 Running BDD Tests..."
+cd /Users/gabrielradureau/Work/Vibe/DanceLessonsCoach
+
+# Run the BDD tests
+test_output=$(go test ./features/... -v 2>&1)
+test_exit_code=$?
+
+echo "$test_output"
+
+# Check for undefined steps
+if echo "$test_output" | grep -q "undefined"; then
+    echo "❌ FAILED: Found undefined steps"
+    exit 1
+fi
+
+# Check for pending steps
+if echo "$test_output" | grep -q "pending"; then
+    echo "❌ FAILED: Found pending steps"
+    exit 1
+fi
+
+# Check for skipped steps
+if echo "$test_output" | grep -q "skipped"; then
+    echo "❌ FAILED: Found skipped steps"
+    exit 1
+fi
+
+# Check if tests passed
+if [ $test_exit_code -eq 0 ]; then
+    echo "✅ All BDD tests passed successfully!"
+    exit 0
+else
+    echo "❌ BDD tests failed"
+    exit 1
+fi