feat: Add plain text CV endpoint and contact form with security

Plain text endpoint:
- Add /text route for plain text CV (for curl/AI crawlers)
- Use k3a/html2text library for HTML-to-text conversion
- Add Plain Text button to hamburger menu with UI translations

Contact form feature:
- Add ContactHandler with proper email service integration
- Add CSRF protection middleware
- Add rate limiting (5 submissions/hour per IP)
- Add honeypot and timing-based bot protection
- Add input validation with detailed error messages
- Add security logging middleware
- Add browser-only middleware for API protection

Code quality:
- Fix all golangci-lint errcheck warnings for w.Write calls
- Remove duplicate getClientIP functions
- Wire up ContactHandler in routes.Setup

main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/juanatsap/cv-site/internal/config"
 	"github.com/juanatsap/cv-site/internal/handlers"
 	"github.com/juanatsap/cv-site/internal/routes"
+	"github.com/juanatsap/cv-site/internal/services"
 	"github.com/juanatsap/cv-site/internal/templates"
 )
 
@@ -41,12 +42,23 @@ func main() {
 		log.Fatalf("❌ Failed to initialize templates: %v", err)
 	}
 
+	// Initialize email service
+	emailService := services.NewEmailService(&services.EmailConfig{
+		SMTPHost:     cfg.Email.SMTPHost,
+		SMTPPort:     cfg.Email.SMTPPort,
+		SMTPUser:     cfg.Email.SMTPUser,
+		SMTPPassword: cfg.Email.SMTPPassword,
+		FromEmail:    cfg.Email.FromEmail,
+		ToEmail:      cfg.Email.ContactEmail,
+	})
+
 	// Initialize handlers
 	cvHandler := handlers.NewCVHandler(templateMgr, cfg.Address())
 	healthHandler := handlers.NewHealthHandler(version)
+	contactHandler := handlers.NewContactHandler(templateMgr, emailService)
 
 	// Setup routes and middleware
-	handler := routes.Setup(cvHandler, healthHandler)
+	handler := routes.Setup(cvHandler, healthHandler, contactHandler)
 
 	// Create server with timeouts
 	server := &http.Server{