Set Indicator Panels' fixup values to that of their attached item

This fixes #BEEmod/BEE2-items#3028, where the timer was moved to a different item.

src/connections.py

@@ -672,12 +672,15 @@ def from_item(self, item: Item) -> None:
 
 def collapse_item(item: Item) -> None:
     """Remove an item with a single input, transferring all IO."""
+    input_conn: Connection
     try:
         [input_conn] = item.inputs
         input_item = input_conn.from_item
     except ValueError:
         raise ValueError('Too many inputs for "{}"!'.format(item.name))
 
+    LOGGER.debug('Merging "{}" into "{}"...', item.name, input_item.name)
+
     input_conn.remove()
 
     input_item.antlines |= item.antlines
@@ -1663,6 +1666,14 @@ def add_item_indicators(
             # instance var, so give it a blank name.
             pan.fixup[const.FixupVars.TOGGLE_OVERLAY] = '-'
 
+        # Overwrite the timer delay value, in case a sign changed ownership.
+        if item.timer is not None:
+            pan.fixup[const.FixupVars.TIM_DELAY] = item.timer
+            pan.fixup[const.FixupVars.TIM_ENABLED] = '1'
+        else:
+            pan.fixup[const.FixupVars.TIM_DELAY] = '99999999999'
+            pan.fixup[const.FixupVars.TIM_ENABLED] = '0'
+
         for outputs, input_cmds in [
             (item.timer_output_start(), pan_item.enable_cmd),
             (item.timer_output_stop(), pan_item.disable_cmd)