Live Editor: add DASP/Sox device connection with full CRUD and COV

Port the DASP transport and Sox protocol stack from sedonaOntrol Java
to Python, enabling live device editing alongside the existing offline
SAX editor. Lazy-loads components on navigation, caches them, and
subscribes to COV events for the active wiresheet.

New files: dasp.py, sox.py, device_session.py, connect_dialog.py,
live_hooks.py. Modified: app_state.py (live-mode state), main.py
(Device menu, COV polling, lazy tree expand), properties.py (Sox
write-through), sax_file.py (structural mutations route through
live_hooks), schema.py (find_manifest helper).

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

properties.py

@@ -32,6 +32,7 @@ import tkinter as tk
 from tkinter import font as tkfont, messagebox, ttk
 
 import app_state
+import live_hooks
 import schema
 import undo
 from sax_dom import (get_component_path, read_meta_property, set_prop_value,
@@ -1132,11 +1133,16 @@ class PropertiesPanel:
             self.status_var.set("No changes to save.")
             return
 
+        live_failures = []
         for element, prop_name, _before, after in changes:
             if prop_name != "meta":
                 set_prop_value(element, prop_name, after)
+                if live_hooks.is_live():
+                    if not live_hooks.live_set_prop_value(element, prop_name, after):
+                        live_failures.append(prop_name)
 
-        undo.push(undo.SlotValueCommand(list(changes)))
+        if not app_state.live_mode:
+            undo.push(undo.SlotValueCommand(list(changes)))
         app_state.mark_dirty()
 
         self.refresh()
@@ -1144,10 +1150,19 @@ class PropertiesPanel:
             self.on_change()
 
         count = len(changes)
-        self.status_var.set(
-            f"{count} slot{'' if count == 1 else 's'} changed. "
-            "Ctrl+S writes the file."
-        )
+        if live_failures:
+            self.status_var.set(
+                f"Written locally but failed on device: {', '.join(live_failures)}"
+            )
+        elif app_state.live_mode:
+            self.status_var.set(
+                f"{count} slot{'' if count == 1 else 's'} written to device."
+            )
+        else:
+            self.status_var.set(
+                f"{count} slot{'' if count == 1 else 's'} changed. "
+                "Ctrl+S writes the file."
+            )
         app_state.set_status(
             f"{self.comp.get('name', '?')}: {count} slot{'' if count == 1 else 's'} changed."
         )