examples: fix E501 and lint issues in enterprise gateway example

- Wrap long strings to satisfy line length
- Replace cli_mode usage not supported by Agent ctor
- Remove trailing whitespace per pycodestyle

Co-authored-by: openhands <openhands@all-hands.dev>

Author: enyst

examples/01_standalone_sdk/26_enterprise_gateway.py

@@ -12,8 +12,8 @@
 
 from pydantic import SecretStr
 
-from openhands.sdk import Agent, Conversation, MessageEvent
-from openhands.sdk.llm import LLM, content_to_str
+from openhands.sdk import Agent, Conversation
+from openhands.sdk.llm import LLM
 
 
 def build_gateway_llm() -> LLM:
@@ -30,7 +30,8 @@ def build_gateway_llm() -> LLM:
         base_url=os.getenv(
             "LLM_BASE_URL", "https://your-corporate-proxy.company.com/api/llm"
         ),
-        # an api_key input is always required but is unused when api keys are passed via extra headers
+        # api_key is required as an input
+        # but unused when API keys are passed via extra headers
         api_key=SecretStr(os.getenv("LLM_API_KEY", "placeholder")),
         custom_llm_provider=os.getenv("LLM_CUSTOM_LLM_PROVIDER", "openai"),
         ssl_verify=ssl_verify,
@@ -58,7 +59,7 @@ def build_gateway_llm() -> LLM:
     llm = build_gateway_llm()
 
     # Create agent and conversation
-    agent = Agent(llm=llm, cli_mode=True)
+    agent = Agent(llm=llm)
     conversation = Conversation(
         agent=agent,
         workspace=os.getcwd(),
@@ -68,7 +69,8 @@ def build_gateway_llm() -> LLM:
     try:
         # Send a message to test the enterprise gateway configuration
         conversation.send_message(
-            "Analyze this codebase and create 3 facts about the current project into FACTS.txt. Do not write code."
+            "Analyze this codebase and create 3 facts about the current project "
+            "into FACTS.txt. Do not write code."
         )
         conversation.run()