Python: Add samples syntax checking with pyright (#3710)

* Add samples syntax checking with pyright

- Add pyrightconfig.samples.json with relaxed type checking but import validation
- Add samples-syntax poe task to check samples for syntax and import errors
- Add samples-syntax to check and pre-commit-check tasks
- Fix 78 sample errors:
  - Update workflow builder imports to use agent_framework_orchestrations
  - Change content type isinstance checks to content.type comparisons
  - Use Content factory methods instead of removed content type classes
  - Fix TypedDict access patterns for Annotation
  - Fix various API mismatches (normalize_messages, ChatMessage.text, role)

* fixed a bunch of samples and tweaks to pre-commit

* updated lock

* updated lock

* fixes

* added lint to samples

python/samples/getting_started/middleware/middleware_termination.py

@@ -10,6 +10,7 @@ from agent_framework import (
     AgentMiddleware,
     AgentResponse,
     ChatMessage,
+    MiddlewareTermination,
     tool,
 )
 from agent_framework.azure import AzureAIAgentClient
@@ -72,8 +73,7 @@ class PreTerminationMiddleware(AgentMiddleware):
                     )
 
                     # Set terminate flag to prevent further processing
-                    context.terminate = True
-                    break
+                    raise MiddlewareTermination
 
         await next(context)
 
@@ -98,7 +98,7 @@ class PostTerminationMiddleware(AgentMiddleware):
                 f"[PostTerminationMiddleware] Maximum responses ({self.max_responses}) reached. "
                 "Terminating further processing."
             )
-            context.terminate = True
+            raise MiddlewareTermination
 
         # Allow the agent to process normally
         await next(context)