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

internal/output.go

@@ -3,8 +3,11 @@ package internal
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/fatih/color"
+
+	"github.com/ivuorinen/gh-action-readme/internal/errors"
 )
 
 // ColoredOutput provides methods for colored terminal output.
@@ -107,3 +110,139 @@ func (co *ColoredOutput) Printf(format string, args ...any) {
 func (co *ColoredOutput) Fprintf(w *os.File, format string, args ...any) {
 	_, _ = fmt.Fprintf(w, format, args...)
 }
+
+// ErrorWithSuggestions prints a ContextualError with suggestions and help.
+func (co *ColoredOutput) ErrorWithSuggestions(err *errors.ContextualError) {
+	if err == nil {
+		return
+	}
+
+	// Print main error message
+	if co.NoColor {
+		fmt.Fprintf(os.Stderr, "❌ %s\n", err.Error())
+	} else {
+		color.Red("❌ %s", err.Error())
+	}
+}
+
+// ErrorWithContext creates and prints a contextual error with suggestions.
+func (co *ColoredOutput) ErrorWithContext(
+	code errors.ErrorCode,
+	message string,
+	context map[string]string,
+) {
+	suggestions := errors.GetSuggestions(code, context)
+	helpURL := errors.GetHelpURL(code)
+
+	contextualErr := errors.New(code, message).
+		WithSuggestions(suggestions...).
+		WithHelpURL(helpURL)
+
+	if len(context) > 0 {
+		contextualErr = contextualErr.WithDetails(context)
+	}
+
+	co.ErrorWithSuggestions(contextualErr)
+}
+
+// ErrorWithSimpleFix prints an error with a simple suggestion.
+func (co *ColoredOutput) ErrorWithSimpleFix(message, suggestion string) {
+	contextualErr := errors.New(errors.ErrCodeUnknown, message).
+		WithSuggestions(suggestion)
+
+	co.ErrorWithSuggestions(contextualErr)
+}
+
+// FormatContextualError formats a ContextualError for display.
+func (co *ColoredOutput) FormatContextualError(err *errors.ContextualError) string {
+	if err == nil {
+		return ""
+	}
+
+	var parts []string
+
+	// Add main error message
+	parts = append(parts, co.formatMainError(err))
+
+	// Add details section
+	if len(err.Details) > 0 {
+		parts = append(parts, co.formatDetailsSection(err.Details)...)
+	}
+
+	// Add suggestions section
+	if len(err.Suggestions) > 0 {
+		parts = append(parts, co.formatSuggestionsSection(err.Suggestions)...)
+	}
+
+	// Add help URL section
+	if err.HelpURL != "" {
+		parts = append(parts, co.formatHelpURLSection(err.HelpURL))
+	}
+
+	return strings.Join(parts, "\n")
+}
+
+// formatMainError formats the main error message with code.
+func (co *ColoredOutput) formatMainError(err *errors.ContextualError) string {
+	mainMsg := fmt.Sprintf("%s [%s]", err.Error(), err.Code)
+	if co.NoColor {
+		return "❌ " + mainMsg
+	}
+	return color.RedString("❌ ") + mainMsg
+}
+
+// formatDetailsSection formats the details section.
+func (co *ColoredOutput) formatDetailsSection(details map[string]string) []string {
+	var parts []string
+
+	if co.NoColor {
+		parts = append(parts, "\nDetails:")
+	} else {
+		parts = append(parts, color.New(color.Bold).Sprint("\nDetails:"))
+	}
+
+	for key, value := range details {
+		if co.NoColor {
+			parts = append(parts, fmt.Sprintf("  %s: %s", key, value))
+		} else {
+			parts = append(parts, fmt.Sprintf("  %s: %s",
+				color.CyanString(key),
+				color.WhiteString(value)))
+		}
+	}
+
+	return parts
+}
+
+// formatSuggestionsSection formats the suggestions section.
+func (co *ColoredOutput) formatSuggestionsSection(suggestions []string) []string {
+	var parts []string
+
+	if co.NoColor {
+		parts = append(parts, "\nSuggestions:")
+	} else {
+		parts = append(parts, color.New(color.Bold).Sprint("\nSuggestions:"))
+	}
+
+	for _, suggestion := range suggestions {
+		if co.NoColor {
+			parts = append(parts, fmt.Sprintf("  • %s", suggestion))
+		} else {
+			parts = append(parts, fmt.Sprintf("  %s %s",
+				color.YellowString("•"),
+				color.WhiteString(suggestion)))
+		}
+	}
+
+	return parts
+}
+
+// formatHelpURLSection formats the help URL section.
+func (co *ColoredOutput) formatHelpURLSection(helpURL string) string {
+	if co.NoColor {
+		return fmt.Sprintf("\nFor more help: %s", helpURL)
+	}
+	return fmt.Sprintf("\n%s: %s",
+		color.New(color.Bold).Sprint("For more help"),
+		color.BlueString(helpURL))
+}