fix: address review feedback from gemini-code-assist

- Move google.genai types import to top of main.py (PEP 8)
- Remove unused import: dataclasses.field in _budget.py, _degradation.py
- Remove unused import: BaseAgent in veronica_governance_plugin.py

Author: amabito

contributing/samples/governance/main.py

@@ -29,23 +29,22 @@
 from google.adk import Runner
 from google.adk.agents import Agent
 from google.adk.sessions import InMemorySessionService
+from google.genai import types
 
-from google.adk_community.governance import (
-    GovernanceConfig,
-    VeronicaGovernancePlugin,
-)
+from google.adk_community.governance import GovernanceConfig
+from google.adk_community.governance import VeronicaGovernancePlugin
 
 logging.basicConfig(level=logging.INFO, format="%(message)s")
 
 
 def main():
   # Configure governance limits
   config = GovernanceConfig(
-      max_cost_usd=0.50,           # org-level: 50 cents
-      agent_max_cost_usd=0.25,     # per-agent: 25 cents
-      failure_threshold=3,          # circuit breaker after 3 failures
+      max_cost_usd=0.50,  # org-level: 50 cents
+      agent_max_cost_usd=0.25,  # per-agent: 25 cents
+      failure_threshold=3,  # circuit breaker after 3 failures
       recovery_timeout_s=30.0,
-      degradation_threshold=0.7,    # degrade at 70% budget
+      degradation_threshold=0.7,  # degrade at 70% budget
       fallback_model="gemini-2.0-flash-lite",
       blocked_tools=["shell_exec"],
       disable_tools_on_degrade=["web_search"],
@@ -67,8 +66,7 @@ def main():
       model="gemini-2.5-flash",
       name="summarizer",
       instruction=(
-          "You summarize text provided to you. Keep summaries to 2-3"
-          " sentences."
+          "You summarize text provided to you. Keep summaries to 2-3 sentences."
       ),
   )
 
@@ -98,8 +96,6 @@ async def run():
         user_id="demo_user",
     )
 
-    from google.genai import types
-
     user_message = types.Content(
         role="user",
         parts=[types.Part(text="What is agent governance?")],

src/google/adk_community/governance/_budget.py

@@ -17,7 +17,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from dataclasses import field
 import threading
 
 

src/google/adk_community/governance/_degradation.py

@@ -17,7 +17,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from dataclasses import field
 import threading
 
 

src/google/adk_community/governance/veronica_governance_plugin.py

@@ -28,7 +28,6 @@
 from typing import Any
 from typing import Optional
 
-from google.adk.agents.base_agent import BaseAgent
 from google.adk.agents.callback_context import CallbackContext
 from google.adk.agents.invocation_context import InvocationContext
 from google.adk.models.llm_request import LlmRequest