Merge origin/main into multi-port-service

Resolve conflicts:
- deployment_context.py: Keep single modify_yaml method from main
- fixturenet-optimism/commands.py: Use modify_yaml helper from main
- deployment_create.py: Keep helm-chart, network-dir, initial-peers options
- deploy_webapp.py: Update create_operation call signature

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

stack_orchestrator/deploy/deployment_create.py

@@ -556,9 +556,9 @@ def create_operation(
     deployment_command_context,
     spec_file,
     deployment_dir,
-    helm_chart,
-    network_dir,
-    initial_peers,
+    helm_chart=False,
+    network_dir=None,
+    initial_peers=None,
     extra_args=(),
 ):
     parsed_spec = Spec(