Fix Outlook folder discovery to find all contact folders

- Scan all stores recursively instead of only the default folder
- Properly release COM objects to avoid leaks
- Better error handling with debug output per store/folder
- Show error message if Outlook is not reachable
- Fallback to default contacts folder if recursive scan finds nothing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/StarfaceOutlookSync/UI/ProfileEditorForm.cs

@@ -142,9 +142,12 @@ namespace StarfaceOutlookSync.UI
                     _outlookFolderPaths = outlook.GetContactFolderPaths();
                 }
             }
-            catch
+            catch (Exception ex)
             {
-                _outlookFolderPaths = new List<string> { "\\\\Kontakte" };
+                MessageBox.Show(
+                    $"Outlook-Kontaktordner konnten nicht geladen werden:\n{ex.Message}\n\nIst Outlook gestartet?",
+                    "Outlook-Verbindung", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                _outlookFolderPaths = new List<string>();
             }
 
             // Bestehende Werte laden