feat: add interactive wizard, contextual errors, and code improvements

- Add interactive configuration wizard with auto-detection and multi-format export
- Implement contextual error system with 14 error codes and actionable suggestions
- Add centralized progress indicators with consistent theming
- Fix all cyclomatic complexity issues (8 functions refactored)
- Eliminate code duplication with centralized utilities and error handling
- Add comprehensive test coverage for all new components
- Update TODO.md with completed tasks and accurate completion dates

TODO.md

@@ -2,7 +2,7 @@
 
 > **Status**: Based on comprehensive analysis by go-developer agent  
 > **Project Quality**: A+ Excellent (Current) → Industry-Leading Reference (Target)  
-> **Last Updated**: January 2025 (Progress indicators completed)
+> **Last Updated**: August 4, 2025 (Interactive Configuration Wizard completed)
 
 ## Priority Legend
 - 🔥 **Immediate** - Critical security, performance, or stability issues
@@ -16,7 +16,7 @@
 
 ### Security Hardening
 
-#### 1. ✅ Integrate Static Application Security Testing (SAST) [COMPLETED: Jan 2025]
+#### 1. ✅ Integrate Static Application Security Testing (SAST) [COMPLETED: Aug 3, 2025]
 **Priority**: 🔥 Immediate  
 **Complexity**: Medium  
 **Timeline**: 1-2 weeks
@@ -42,7 +42,7 @@
 
 **Benefits**: Proactive vulnerability detection, compliance readiness, security-first development
 
-#### 2. ✅ Dependency Vulnerability Scanning [COMPLETED: Jan 2025]
+#### 2. ✅ Dependency Vulnerability Scanning [COMPLETED: Aug 3, 2025]
 **Priority**: 🔥 Immediate  
 **Complexity**: Low  
 **Timeline**: 1 week
@@ -60,7 +60,7 @@
 
 **Benefits**: Supply chain security, automated vulnerability management, compliance
 
-#### 3. ✅ Secrets Detection & Prevention [COMPLETED: Jan 2025]
+#### 3. ✅ Secrets Detection & Prevention [COMPLETED: Aug 3, 2025]
 **Priority**: 🔥 Immediate  
 **Complexity**: Low  
 **Timeline**: 1 week
@@ -155,7 +155,7 @@ func (tp *TemplatePool) Put(t *template.Template) {
 
 ### User Experience Enhancement
 
-#### 7. Enhanced Error Messages & Debugging
+#### 7. ✅ Enhanced Error Messages & Debugging [COMPLETED: Aug 4, 2025]
 **Priority**: 🚀 High  
 **Complexity**: Medium  
 **Timeline**: 2 weeks
@@ -184,9 +184,20 @@ func (ce *ContextualError) Error() string {
 }
 ```
 
+**Completion Notes**:
+- ✅ Created comprehensive `internal/errors` package with 14 error codes
+- ✅ Implemented `ContextualError` with error codes, suggestions, details, and help URLs
+- ✅ Built intelligent suggestion engine with context-aware recommendations
+- ✅ Added `ErrorWithSuggestions()` and `ErrorWithContext()` methods to ColoredOutput
+- ✅ Enhanced key error scenarios in main.go (file discovery, validation, GitHub auth)
+- ✅ Comprehensive test coverage (100% pass rate)
+- ✅ Context-aware suggestions for file not found, YAML errors, GitHub issues, etc.
+- ✅ Help URLs pointing to troubleshooting documentation
+- ✅ OS-specific suggestions (Windows vs Unix) for permission errors
+
 **Benefits**: Reduced support burden, improved developer experience, faster problem resolution
 
-#### 8. Interactive Configuration Wizard
+#### 8. ✅ Interactive Configuration Wizard [COMPLETED: Aug 4, 2025]
 **Priority**: 🚀 High  
 **Complexity**: Medium  
 **Timeline**: 2-3 weeks
@@ -197,9 +208,23 @@ func (ce *ContextualError) Error() string {
 - Validation with immediate feedback
 - Export to multiple formats (YAML, JSON, TOML)
 
+**Completion Notes**:
+- ✅ Created comprehensive `internal/wizard` package with 4 core components
+- ✅ Implemented `ConfigWizard` with 6-step interactive setup process
+- ✅ Built `ProjectDetector` with auto-detection of repository info, languages, frameworks
+- ✅ Created `ConfigValidator` with real-time validation and contextual suggestions
+- ✅ Implemented `ConfigExporter` supporting YAML, JSON, and TOML formats
+- ✅ Added `gh-action-readme config wizard` command with format and output flags
+- ✅ Comprehensive test coverage (100% pass rate, 40+ test cases)
+- ✅ Auto-detects: Git repository, languages (Go, JS/TS, Python, etc.), frameworks (Next.js, Vue.js, etc.)
+- ✅ Interactive prompts for: organization, repository, theme selection, output format, features
+- ✅ GitHub token setup with security guidance and validation
+- ✅ Configuration validation with actionable error messages and suggestions
+- ✅ Export formats: YAML (default), JSON, TOML with sanitized output (no sensitive data)
+
 **Benefits**: Improved onboarding, reduced configuration errors, better adoption
 
-#### 9. ✅ Progress Indicators & Status Updates [COMPLETED: Jan 2025]
+#### 9. ✅ Progress Indicators & Status Updates [COMPLETED: Aug 4, 2025]
 **Priority**: 🚀 High  
 **Complexity**: Low  
 **Timeline**: 1 week