fix: Properly URL-encode labels parameter for API requests

- Add quotes around label values to match API requirements
- Fix label filtering for labels with spaces (e.g. 'aa aa')
- Ensure proper URL encoding as required by server
- Maintains existing pagination and filtering functionality

readeck/Data/API/API.swift

@@ -241,7 +241,9 @@ class API: PAPI {
         }
         
         if let tag {
-            queryItems.append(URLQueryItem(name: "labels", value: tag))
+            // URL-encode label with quotes for proper API handling
+            let encodedTag = "\"\(tag)\""
+            queryItems.append(URLQueryItem(name: "labels", value: encodedTag))
         }
         
         if !queryItems.isEmpty {

readeck/Data/Utils/LabelUtils.swift

@@ -1,14 +1,12 @@
 import Foundation
 
 struct LabelUtils {
-    /// Splits a label input string by spaces and returns individual trimmed labels
+    /// Processes a label input string and returns it as a single trimmed label
-    /// - Parameter input: The input string containing one or more labels separated by spaces
+    /// - Parameter input: The input string containing a label (spaces are allowed)
-    /// - Returns: Array of individual trimmed labels, excluding empty strings
+    /// - Returns: Array containing the trimmed label, or empty array if input is empty
     static func splitLabelsFromInput(_ input: String) -> [String] {
-        return input
+        let trimmed = input.trimmingCharacters(in: .whitespacesAndNewlines)
-            .components(separatedBy: " ")
+        return trimmed.isEmpty ? [] : [trimmed]
-            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
-            .filter { !$0.isEmpty }
     }
     
     /// Filters out labels that already exist in current or available labels