Add User Manager panel for sys::UserService components

New user_service_view.py with table of sys::User children, add/edit/delete
dialogs, SHA-1 credential hashing, 32-bit permission bitmask (4 groups x 7
flags), 8-bit provisioning byte, and undo support. Wired into main.py with
context menu entry, panel management, history navigation, and live-mode DOM
resolution for correct display on connected devices.

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

main.py

@@ -18,6 +18,7 @@ import properties
 import sax_file
 import schema
 import undo
+import user_service_view
 import wiresheet
 from sax_dom import (find_component_by_path, find_parent_element, get_component_path,
                      read_meta_property, update_meta_property)
@@ -78,6 +79,7 @@ HISTORY_LIMIT = 50
 VIEW_SHEET = "sheet"
 VIEW_PROPERTIES = "properties"
 VIEW_LINKS = "links"
+VIEW_USERS = "users"
 
 # Tk class names of the widgets that own the keyboard while they have focus. Del and
 # Backspace mean "edit this text" in each of them, never "delete the selected component".
@@ -122,6 +124,7 @@ show_left_column_var = None
 properties_panel = None
 link_panel = None
 kits_panel = None
+user_service_panel = None
 
 # The sheet to put the tree back on when a sheet change is refused because of unsaved
 # edits, and the flag that stops the restoring selection from being read as a fresh
@@ -189,6 +192,12 @@ def refresh_all_views():
         else:
             close_editor_panel(force=True)
 
+    if user_service_panel is not None:
+        if _component_in_document(user_service_panel.comp):
+            user_service_panel.refresh()
+        else:
+            close_editor_panel(force=True)
+
 
 def _component_in_document(comp):
     root = app_state.xml_root_element
@@ -210,7 +219,7 @@ def delete_component(comp):
     than going through refresh_all_views, so the panel would otherwise be left describing
     a component the document no longer has.
     """
-    panel = properties_panel or link_panel
+    panel = properties_panel or link_panel or user_service_panel
     showing = panel is not None and panel.comp is comp
     if sax_file.execute_cascading_deletion(comp) and showing:
         close_editor_panel(force=True)
@@ -218,7 +227,8 @@ def delete_component(comp):
 
 def editor_panel_showing():
     """Whether something other than the wiresheet has the editor pane."""
-    return properties_panel is not None or link_panel is not None or kits_panel is not None
+    return (properties_panel is not None or link_panel is not None
+            or kits_panel is not None or user_service_panel is not None)
 
 
 def _take_editor_pane():
@@ -330,6 +340,38 @@ def dismiss_link_view(restore_canvas=True):
         _give_editor_pane_back()
 
 
+def show_user_service(comp):
+    """Puts the User Manager for a sys::UserService in the editor pane."""
+    global user_service_panel
+    if comp is None:
+        return
+
+    if not close_editor_panel():
+        return
+
+    _take_editor_pane()
+    user_service_panel = user_service_view.build_user_service_panel(
+        frame_editor, comp, on_change=refresh_all_views,
+        on_close=dismiss_user_service,
+    )
+    user_service_panel.frame.pack(fill=tk.BOTH, expand=True)
+    record_visit(VIEW_USERS, comp)
+    app_state.set_status(f"User Manager: {comp.get('name', '?')}")
+
+
+def dismiss_user_service(restore_canvas=True):
+    """Takes the User Manager down and gives the pane back."""
+    global user_service_panel
+    if user_service_panel is None:
+        return
+
+    user_service_panel.destroy()
+    user_service_panel = None
+
+    if restore_canvas:
+        _give_editor_pane_back()
+
+
 def show_kits():
     """Puts the kit table in the editor pane, in place of the wiresheet."""
     global kits_panel
@@ -378,6 +420,9 @@ def close_editor_panel(force=False):
     if kits_panel is not None:
         dismiss_kits()
         return True
+    if user_service_panel is not None:
+        dismiss_user_service()
+        return True
     if properties_panel is None:
         return True
     if force:
@@ -1207,6 +1252,11 @@ def fill_component_popup(menu, comp):
         label="Link View",
         command=lambda: show_link_view(comp),
     )
+    if user_service_view.is_user_service(comp):
+        menu.add_command(
+            label="User Manager",
+            command=lambda: show_user_service(comp),
+        )
     menu.add_separator()
     menu.add_command(
         label="Delete Component",
@@ -1644,6 +1694,8 @@ def _show_history_entry(position):
             _show_sheet_entry(element)
         elif kind == VIEW_PROPERTIES:
             show_properties(element)
+        elif kind == VIEW_USERS:
+            show_user_service(element)
         else:
             show_link_view(element)
     finally:
@@ -1707,7 +1759,7 @@ def on_tree_filled():
 
     # A different file has no such component, and a rebuild after a delete may have taken
     # it. Neither is a moment to ask about edits that now have nowhere to go.
-    panel = properties_panel or link_panel
+    panel = properties_panel or link_panel or user_service_panel
     if panel is not None and not _component_in_document(panel.comp):
         close_editor_panel(force=True)