fix: editable alias in server dialog + Ctrl+Z undo for all input fields

- Alias field no longer disabled when editing server profile
- Duplicate alias check on rename, session pool migration
- Enable undo (Ctrl+Z) on all CTkEntry widgets across the project

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gui/tabs/files_tab.py

@@ -131,6 +131,8 @@ class FilesTab(ctk.CTkFrame):
         self._local_path_entry = ctk.CTkEntry(left_header, height=28)
         self._local_path_entry.pack(side="left", fill="x", expand=True, padx=(4, 0))
         self._local_path_entry.bind("<Return>", lambda e: self._local_go_to_path())
+        # Enable undo functionality
+        self._local_path_entry._entry.config(undo=True)
 
         self._local_list = FileListWidget(
             left_pane,
@@ -177,6 +179,8 @@ class FilesTab(ctk.CTkFrame):
         self._remote_path_entry = ctk.CTkEntry(right_header, height=28)
         self._remote_path_entry.pack(side="left", fill="x", expand=True, padx=(4, 0))
         self._remote_path_entry.bind("<Return>", lambda e: self._remote_go_to_path())
+        # Enable undo functionality
+        self._remote_path_entry._entry.config(undo=True)
 
         self._remote_list = FileListWidget(
             right_pane,

gui/tabs/totp_tab.py

@@ -106,6 +106,8 @@ class TOTPTab(ctk.CTkFrame):
             font=ctk.CTkFont(family="Consolas", size=12)
         )
         self.secret_entry.pack(side="left", fill="x", expand=True, padx=(0, 5))
+        # Enable undo functionality
+        self.secret_entry._entry.config(undo=True)
 
         self.show_secret_btn = ctk.CTkButton(
             entry_row, text=t("show"), width=70,