Blender 5.0 compat + STB XML import + sequence/stamps improvements

- Fix Blender 5.0 API: active_sequence_strip → active_strip, bracket
  property access on AddonPreferences, _RestrictContext during register()
- Fix new_effect() frame_end → length for Blender 5.0
- Fix OTIO adapter kwargs (rate/ignore_timecode_mismatch only for cmx_3600)
- Fix OTIO global_start_time RationalTime → int conversion
- Add Import STB XML operator with movie strip import and XML patching
  for Storyboard Pro transitions missing <alignment>
- Add Create Sequence Strip operator (select shots → create sequence)
- Improve Set Stamps: channel at top, no conflict with existing strips,
  use raw strip names in templates
- TVSHOW episode fixes: sequence loading, episode creation
- Kitsu: new_asset, new_episode, admin_connect fix, gazu version pin
- Fix escape warnings in file_utils regex patterns
- Guard handler registration against duplicates

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

operators/casting.py

@@ -53,7 +53,7 @@ class VSETB_OT_casting_replace(Operator):
             item = self.assets.add()
             item.name = asset.tracker_name
 
-        strip = context.active_sequence_strip
+        strip = context.active_strip
         asset_casting_index = strip.vsetb_strip_settings.casting_index
         active_asset = strip.vsetb_strip_settings.casting[asset_casting_index].asset
 
@@ -87,7 +87,7 @@ class VSETB_OT_casting_add(Operator):
     #asset_name : EnumProperty(name='', items=get_scene_settings().active_project.get('asset_items', []))
     @classmethod
     def poll(cls, context):
-        active_strip = context.active_sequence_strip
+        active_strip = context.active_strip
         if active_strip:
             return True
 
@@ -135,7 +135,7 @@ class VSETB_OT_casting_remove(Operator):
 
     @classmethod
     def poll(cls, context):
-        active_strip = context.active_sequence_strip
+        active_strip = context.active_strip
         if active_strip:
             return True
 
@@ -190,7 +190,7 @@ class VSETB_OT_casting_move(Operator):
 
     @classmethod
     def poll(cls, context):
-        active_strip = context.active_sequence_strip
+        active_strip = context.active_strip
         if active_strip:
             return True
 
@@ -231,7 +231,7 @@ class VSETB_OT_copy_casting(Operator):
     def poll(cls, context):
         if not context.scene.sequence_editor:
             return
-        active_strip = context.active_sequence_strip
+        active_strip = context.active_strip
         strip_settings = get_strip_settings()
         
         if active_strip and strip_settings.casting:
@@ -256,7 +256,7 @@ class VSETB_OT_paste_casting(Operator):
 
     @classmethod
     def poll(cls, context):
-        return context.active_sequence_strip
+        return context.active_strip
 
     def invoke(self, context, event):
         self.mode = 'REPLACE'
@@ -279,7 +279,7 @@ class VSETB_OT_paste_casting(Operator):
         casting_datas = json.loads(CASTING_BUFFER.read_text())
         casting_ids = set(c['id'] for c in casting_datas)
 
-        for strip in context.selected_sequences:
+        for strip in context.selected_strips:
             strip_settings = strip.vsetb_strip_settings
 
             if self.mode == 'REPLACE':
@@ -317,7 +317,7 @@ class VSETB_OT_copy_metadata(Operator):
 
     @classmethod
     def poll(cls, context):
-        return context.selected_sequences and context.active_sequence_strip
+        return context.selected_strips and context.active_strip
 
     def execute(self, context):
         prefs = get_addon_prefs()
@@ -329,11 +329,11 @@ class VSETB_OT_copy_metadata(Operator):
         if not metadata:
             self.report({'ERROR'}, f'No Metadata named {self.metadata}')
 
-        active_strip = context.active_sequence_strip
+        active_strip = context.active_strip
         metadata_value = getattr(active_strip.vsetb_strip_settings.metadata, metadata)
         
-        for strip in context.selected_sequences:
-            if strip == context.active_sequence_strip:
+        for strip in context.selected_strips:
+            if strip == context.active_strip:
                 continue
 
             setattr(strip.vsetb_strip_settings.metadata, metadata, metadata_value)
@@ -341,6 +341,68 @@ class VSETB_OT_copy_metadata(Operator):
         return {"FINISHED"}
 
 
+def get_asset_type_items(self, context):
+    settings = get_scene_settings()
+    project = settings.active_project
+    if project and project.asset_types:
+        return [(t.name, t.name, '') for t in project.asset_types]
+    return [('Character', 'Character', '')]
+
+
+class VSETB_OT_casting_create_asset(Operator):
+    bl_idname = "vse_toolbox.casting_create_asset"
+    bl_label = "Create & Cast Asset"
+    bl_description = "Create a new asset in Kitsu and add to casting"
+    bl_options = {"REGISTER", "UNDO"}
+
+    asset_name: StringProperty(name="Name")
+    asset_type: EnumProperty(name="Type", items=get_asset_type_items)
+    description: StringProperty(name="Description")
+
+    @classmethod
+    def poll(cls, context):
+        settings = get_scene_settings()
+        return settings.active_project
+
+    def invoke(self, context, event):
+        return context.window_manager.invoke_props_dialog(self)
+
+    def execute(self, context):
+        prefs = get_addon_prefs()
+        settings = get_scene_settings()
+        project = settings.active_project
+        tracker = prefs.tracker
+
+        try:
+            new_asset_data = tracker.new_asset(
+                self.asset_name, self.asset_type,
+                project=project.id, description=self.description
+            )
+        except Exception as e:
+            self.report({'ERROR'}, str(e))
+            return {'CANCELLED'}
+
+        # Add to local project assets
+        asset = project.assets.add()
+        asset.name = new_asset_data['id']
+        asset.id = new_asset_data['id']
+        asset.tracker_name = new_asset_data['name']
+        asset.asset_type = self.asset_type
+
+        # Cast to selected shot strips
+        strips = get_strips('Shots', selected_only=True)
+        for strip in strips:
+            strip_settings = strip.vsetb_strip_settings
+            cast_item = strip_settings.casting.add()
+            cast_item.name = new_asset_data['id']
+            cast_item.id = new_asset_data['id']
+            cast_item['_name'] = self.asset_name
+            strip_settings.casting.update()
+
+        self.report({'INFO'}, f"Created asset '{self.asset_name}' and cast to {len(strips)} shots")
+        return {'FINISHED'}
+
+
 classes = (
     VSETB_OT_casting_add,
     VSETB_OT_casting_remove,
@@ -348,7 +410,8 @@ classes = (
     VSETB_OT_copy_casting,
     VSETB_OT_paste_casting,
     VSETB_OT_casting_replace,
-    VSETB_OT_copy_metadata
+    VSETB_OT_copy_metadata,
+    VSETB_OT_casting_create_asset,
 )
 
 def register():