fix(backend): relax CSP for Swagger UI docs

- Allow 'unsafe-inline' and 'unsafe-eval' scripts on /docs routes
- Swagger UI requires inline scripts to function properly
- Keep strict CSP for all other API routes

backend/internal/middleware/security_headers.go

@@ -1,13 +1,20 @@
 package middleware
 
-import "net/http"
+import (
+	"net/http"
+	"strings"
+)
 
 // SecurityHeadersMiddleware adds essential security headers to all responses
 // Based on OWASP guidelines
 func SecurityHeadersMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		// Prevent clickjacking
-		w.Header().Set("X-Frame-Options", "DENY")
+		// Prevent clickjacking (allow framing for Swagger UI)
+		if strings.HasPrefix(r.URL.Path, "/docs") {
+			w.Header().Set("X-Frame-Options", "SAMEORIGIN")
+		} else {
+			w.Header().Set("X-Frame-Options", "DENY")
+		}
 
 		// Prevent MIME sniffing
 		w.Header().Set("X-Content-Type-Options", "nosniff")
@@ -21,8 +28,13 @@ func SecurityHeadersMiddleware(next http.Handler) http.Handler {
 		// Permissions policy (disable potentially dangerous features)
 		w.Header().Set("Permissions-Policy", "geolocation=(), microphone=(), camera=()")
 
-		// Content Security Policy - adjust as needed for your frontend
-		w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'")
+		// Content Security Policy - relaxed for Swagger UI docs
+		if strings.HasPrefix(r.URL.Path, "/docs") {
+			// Swagger UI needs unsafe-inline and unsafe-eval for its scripts
+			w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:")
+		} else {
+			w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'")
+		}
 
 		// HSTS - uncomment in production with HTTPS
 		// w.Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains")