refactor: go fix ftw

internal/handlers/auth_handler_test.go

@@ -1364,7 +1364,7 @@ func TestAuthHandler_ConcurrentAccess(t *testing.T) {
 		concurrency := 10
 		done := make(chan bool, concurrency)
 
-		for i := 0; i < concurrency; i++ {
+		for range concurrency {
 			go func() {
 				req := createLoginRequest(`{"username":"testuser","password":"Password123!"}`)
 				w := httptest.NewRecorder()
@@ -1376,7 +1376,7 @@ func TestAuthHandler_ConcurrentAccess(t *testing.T) {
 			}()
 		}
 
-		for i := 0; i < concurrency; i++ {
+		for range concurrency {
 			<-done
 		}
 	})

internal/handlers/page_handler.go

@@ -115,10 +115,7 @@ func NewPageHandler(templatesDir string, authService AuthServiceInterface, postR
 				if start >= len(s) {
 					return ""
 				}
-				end := start + length
-				if end > len(s) {
-					end = len(s)
-				}
+				end := min(start+length, len(s))
 				return s[start:end]
 			},
 			"upper": strings.ToUpper,