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>

resources/trackers/kitsu.py

@@ -15,7 +15,7 @@ from vse_toolbox.file_utils import install_module, norm_str
 from vse_toolbox.resources.trackers.tracker import Tracker
 
 try:
-    gazu = install_module('gazu')
+    gazu = install_module('gazu', package_name='gazu>=1.0,<2.0')
 except Exception as e:
     print('Could not install gazu')
     print(e)
@@ -32,10 +32,15 @@ class Kitsu(Tracker):
     admin_password : StringProperty(subtype='PASSWORD')
     
     def admin_connect(self):
-        url = self.url
+        url = expandvars(self.url)
+        if not url:
+            raise ConnectionError("No Kitsu URL configured")
+
         if not url.endswith('/api'):
             url += '/api'
 
+        gazu.client.set_host(url)
+
         login = expandvars(self.admin_login or self.login)
         password = expandvars(self.admin_password or self.password)
 
@@ -347,6 +352,26 @@ class Kitsu(Tracker):
             status = self.get_task_status(status)
         return gazu.task.new_task(entity, task_type=task_type, task_status=status)
 
+    def new_asset(self, name, asset_type_name, project=None, description="", episode=None):
+        project = self.get_project(project)
+        project_dict = {'id': self.get_id(project)}
+        asset_type = gazu.asset.get_asset_type_by_name(asset_type_name)
+        if not asset_type:
+            raise ValueError(f"Asset type '{asset_type_name}' not found in Kitsu")
+        episode_dict = {'id': self.get_id(episode)} if episode else None
+        return gazu.asset.new_asset(
+            project_dict, asset_type, name,
+            description=description, episode=episode_dict
+        )
+
+    def new_episode(self, name, project=None):
+        project = self.get_project(project)
+        return gazu.shot.new_episode({'id': self.get_id(project)}, name)
+
+    def update_project(self, project=None):
+        """Refresh project data — no-op for now, caller should reload via load_projects."""
+        pass
+
     def new_sequence(self, sequence, episode=None, project=None):
         project = self.get_project(project)