fix(dcim): Handle missing Virtual Circuit Termination gracefully

Replace direct attribute access with try-except to catch
ObjectDoesNotExist when virtual_circuit_termination relation is missing.
Prevents errors when rendering Virtual Circuits Panel with broken or
missing terminations.

Fixes #21808

docs/plugins/development/search.md

@@ -1,12 +1,14 @@
 # Search
 
-Plugins can define and register their own models to extend NetBox's core search functionality. Typically, a plugin will include a file named `search.py`, which holds all search indexes for its models (see the example below).
+Plugins can define and register their own models to extend NetBox's core search functionality. Typically, a plugin will include a file named `search.py`, which holds all search indexes for its models.
 
-```python
+```python title="search.py"
 # search.py
-from netbox.search import SearchIndex
+from netbox.search import SearchIndex, register_search
+
 from .models import MyModel
 
+@register_search
 class MyModelIndex(SearchIndex):
     model = MyModel
     fields = (
@@ -17,15 +19,11 @@ class MyModelIndex(SearchIndex):
     display_attrs = ('site', 'device', 'status', 'description')
 ```
 
-Fields listed in `display_attrs` will not be cached for search, but will be displayed alongside the object when it appears in global search results. This is helpful for conveying to the user additional information about an object.
+Decorate each `SearchIndex` subclass with `@register_search` to register it with NetBox. When using the default `search.py` module, no additional `indexes = [...]` list is required.
 
-To register one or more indexes with NetBox, define a list named `indexes` at the end of this file:
-
-```python
-indexes = [MyModelIndex]
-```
+Fields listed in `display_attrs` are not cached for matching, but they are displayed alongside the object in global search results to provide additional context.
 
 !!! tip
-    The path to the list of search indexes can be modified by setting `search_indexes` in the PluginConfig instance.
+    The legacy `indexes = [...]` list remains supported via `PluginConfig.search_indexes` for backward compatibility and custom loading patterns.
 
 ::: netbox.search.SearchIndex

netbox/dcim/ui/panels.py

@@ -1,4 +1,5 @@
 from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ObjectDoesNotExist
 from django.template.loader import render_to_string
 from django.utils.translation import gettext_lazy as _
 
@@ -532,8 +533,14 @@ class VirtualCircuitPanel(panels.ObjectPanel):
 
     def render(self, context):
         obj = context.get('object')
-        if not obj or not obj.is_virtual or not obj.virtual_circuit_termination:
+        if not obj or not obj.is_virtual:
             return ''
+
+        try:
+            obj.virtual_circuit_termination
+        except ObjectDoesNotExist:
+            return ''
+
         ctx = self.get_context(context)
         return render_to_string(self.template_name, ctx, request=ctx.get('request'))