Scope google_genai snippet markers to the excerpted code (#346)

The docs page for the Google GenAI plugin pulled four of these snippets
with `selectedLines` ranges that started partway into the file, so
snipsync rendered each one with a leading `# ...` elision marker. The
marker also sits at column 0, which zeroes out the common indent prefix
and suppresses snipsync's dedenting, so the worker excerpts rendered
indented as well.

Move the SNIPSTART/SNIPEND markers to wrap exactly the code the page
shows, so the page can drop `selectedLines` entirely:

- tools/run_worker.py: the Worker construction with its activity
- vertex_ai/run_worker.py: the vertexai=True client and plugin
- mcp/run_worker.py: echo_session through the plugin registration
- streaming/run_workflow.py: consume() through the Client.connect that
  installs the Pydantic data converter

The streaming range was also wrong, not just offset: it began at a
dangling `if` inside consume() and omitted the stream.subscribe() call
that the surrounding prose describes.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: brianstrauch

google_genai/mcp/run_worker.py

@@ -5,7 +5,6 @@
 ``list_tools`` / ``call_tool`` as activities.
 """
 
-# @@@SNIPSTART python-google-genai-mcp-worker
 import asyncio
 import os
 import sys
@@ -25,6 +24,7 @@
 ECHO_SERVER = str(Path(__file__).parent / "echo_mcp_server.py")
 
 
+# @@@SNIPSTART python-google-genai-mcp-worker
 @asynccontextmanager
 async def echo_session() -> AsyncIterator[ClientSession]:
     """Yield a connected, initialized session to the stdio echo MCP server."""
@@ -38,6 +38,7 @@ async def echo_session() -> AsyncIterator[ClientSession]:
 async def main() -> None:
     genai_client = genai.Client(api_key=os.environ["GOOGLE_API_KEY"])
     plugin = GoogleGenAIPlugin(genai_client, mcp_servers={"echo": echo_session})
+    # @@@SNIPEND
 
     client = await Client.connect(
         os.environ.get("TEMPORAL_ADDRESS", "localhost:7233"),
@@ -55,4 +56,3 @@ async def main() -> None:
 
 if __name__ == "__main__":
     asyncio.run(main())
-# @@@SNIPEND

google_genai/streaming/run_workflow.py

@@ -1,6 +1,5 @@
 """Start the streaming workflow and consume model chunks live."""
 
-# @@@SNIPSTART python-google-genai-streaming-run-workflow
 import asyncio
 import os
 from datetime import timedelta
@@ -17,6 +16,7 @@
 STREAM_TIMEOUT = 60.0
 
 
+# @@@SNIPSTART python-google-genai-streaming-run-workflow
 async def consume(client: Client, workflow_id: str) -> None:
     """Subscribe to the "gemini" topic and print chunks as the model produces them."""
     stream = WorkflowStreamClient.create(client, workflow_id)
@@ -41,6 +41,7 @@ async def main() -> None:
         os.environ.get("TEMPORAL_ADDRESS", "localhost:7233"),
         data_converter=pydantic_data_converter,
     )
+    # @@@SNIPEND
     workflow_id = "google-genai-streaming"
 
     handle = await client.start_workflow(
@@ -63,4 +64,3 @@ async def main() -> None:
 
 if __name__ == "__main__":
     asyncio.run(main())
-# @@@SNIPEND

google_genai/tools/run_worker.py

@@ -1,6 +1,5 @@
 """Worker for the tools sample."""
 
-# @@@SNIPSTART python-google-genai-tools-worker
 import asyncio
 import os
 
@@ -21,16 +20,17 @@ async def main() -> None:
         plugins=[plugin],
     )
 
+    # @@@SNIPSTART python-google-genai-tools-worker
     worker = Worker(
         client,
         task_queue="google-genai-tools",
         workflows=[ToolsWorkflow],
         activities=[get_weather],
     )
+    # @@@SNIPEND
     print("Worker started. Ctrl+C to exit.")
     await worker.run()
 
 
 if __name__ == "__main__":
     asyncio.run(main())
-# @@@SNIPEND

google_genai/vertex_ai/run_worker.py

@@ -5,7 +5,6 @@
 ``GOOGLE_APPLICATION_CREDENTIALS`` to a service-account key file.
 """
 
-# @@@SNIPSTART python-google-genai-vertex-ai-worker
 import asyncio
 import os
 
@@ -18,12 +17,14 @@
 
 
 async def main() -> None:
+    # @@@SNIPSTART python-google-genai-vertex-ai-worker
     genai_client = genai.Client(
         vertexai=True,
         project=os.environ["GOOGLE_CLOUD_PROJECT"],
         location=os.environ.get("GOOGLE_CLOUD_LOCATION", "us-central1"),
     )
     plugin = GoogleGenAIPlugin(genai_client)
+    # @@@SNIPEND
 
     client = await Client.connect(
         os.environ.get("TEMPORAL_ADDRESS", "localhost:7233"),
@@ -41,4 +42,3 @@ async def main() -> None:
 
 if __name__ == "__main__":
     asyncio.run(main())
-# @@@SNIPEND