v1.8.17: revert broken undo, keep only alias-edit feature

Fully reverted sidebar, files_tab, totp_tab, server_dialog to v1.8.10
base. Removed all entry_undo bindings that broke Ctrl+V paste globally.
Only alias editing feature preserved (editable alias + rename support).

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

gui/tabs/files_tab.py

@@ -13,7 +13,6 @@ from tkinter import messagebox, filedialog
 import customtkinter as ctk
 
 from core.i18n import t
-from gui.widgets.entry_undo import enable_undo
 from core.ssh_client import SFTPSession
 from gui.widgets.file_list import FileListWidget
 
@@ -132,7 +131,6 @@ 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(self._local_path_entry)
 
         self._local_list = FileListWidget(
             left_pane,
@@ -179,7 +177,6 @@ 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(self._remote_path_entry)
 
         self._remote_list = FileListWidget(
             right_pane,