fix(qt): auto-close Plugins manager, read-only field styling, RLock-safe heirs persistence

GUI / plugin lifecycle:
- Auto-close Electrum's native 'Electrum Plugins' manager dialog after the
  BAL plugin is hot-enabled. Electrum 4.7.x no longer calls the old init_qt
  hook, so the close is now triggered from the create_status_bar, init_menubar
  and load_wallet hooks (fired when reload_windows() recreates the window).
- Robust dialog matching (isinstance / class name / localized window title) to
  cope with zipimport module-identity mismatches.
- Robust dismissal of the modal dialog (reject()/done()/close()) with a retry
  schedule [400, 800, 1500] ms; if it still cannot be closed, fall back to
  bringing it to the front (showNormal/raise_/activateWindow) so it never
  lingers hidden in the background. Counting only visible top-levels avoids
  treating an already-closed dialog as still open.

Read-only field styling:
- Paint the locked Delivery time / Check Alive date editors and the mining-fee
  spinbox with a light-grey background (#f0f0f0) so the user can see at a glance
  that they are not editable outside the 'Build your will' wizard; the styling
  is cleared when the fields are made editable again.

Pickle/RLock crash on 'Build will':
- heirs.save() now sanitises the heirs mapping via _json_safe() before handing
  it to json_db.put(), which deep-copies the value. A live runtime object
  (holding a threading.RLock) slipping into an heir value previously raised
  'TypeError: cannot pickle _thread.RLock object' and aborted the task; such
  values are now coerced to str and logged with their path.
- init_heirs_to_locktime() coerces the locktime to a plain serializable scalar.
- log_error() now accepts both a sys.exc_info() triple and a single exception
  instance, fixing the secondary 'TypeError object is not subscriptable' that
  masked the real error.

bal/gui/qt/common.py

@@ -53,10 +53,10 @@ from PyQt6.QtCore import (QDateTime, QModelIndex, QPersistentModelIndex, Qt,
                           QTimer, pyqtSignal)
 from PyQt6.QtGui import (QColor, QPainter, QPalette, QStandardItem,
                          QStandardItemModel)
-from PyQt6.QtWidgets import (QAbstractItemView, QCheckBox, QComboBox,
-                             QDateTimeEdit, QGridLayout, QHBoxLayout, QLabel,
-                             QLineEdit, QTextEdit, QMenu, QMenuBar, QPushButton,
-                             QScrollArea, QSizePolicy, QSpinBox,
+from PyQt6.QtWidgets import (QAbstractItemView, QAbstractSpinBox, QCheckBox,
+                             QComboBox, QDateTimeEdit, QGridLayout, QHBoxLayout,
+                             QLabel, QLineEdit, QTextEdit, QMenu, QMenuBar,
+                             QPushButton, QScrollArea, QSizePolicy, QSpinBox,
                              QStackedWidget, QStyle, QStyleOptionFrame,
                              QVBoxLayout, QWidget, QDialog)
 
@@ -116,18 +116,34 @@ class CheckAliveError(Exception):
 
 
 def log_error(exec_info, window=None):
-    _logger.error(f"LOG_ERROR: {exec_info}")
-    #tb = traceback.format_exc()
-    try:
-        tb=exec_info[1]
-        _logger.error(tb)
-    except Exception:
-        tb = traceback.format_exc()
-        _logger.error(tb)
+    """Log an error and optionally show it.
 
+    ``exec_info`` may be either a ``sys.exc_info()`` triple
+    ``(type, value, traceback)`` or a single exception instance (callers use
+    both forms), so we handle both and always try to log a full traceback.
+    """
+    _logger.error(f"LOG_ERROR: {exec_info}")
+    exc = None
+    if isinstance(exec_info, BaseException):
+        exc = exec_info
+    elif isinstance(exec_info, (tuple, list)) and len(exec_info) >= 2:
+        # sys.exc_info() form: the exception instance is the 2nd element.
+        exc = exec_info[1]
+    try:
+        if exc is not None:
+            _logger.error(
+                "".join(
+                    traceback.format_exception(type(exc), exc, exc.__traceback__)
+                )
+            )
+        else:
+            _logger.error(traceback.format_exc())
+    except Exception:
+        _logger.error(traceback.format_exc())
 
     if window is not None:
-        window.show_error(exec_info)
+        # show_error expects a human-readable message, not a triple.
+        window.show_error(str(exc) if exc is not None else str(exec_info))