test: update smoke and regression suites for dual-renderer paths

Offscreen harnesses now resize+show before load, use per-instance webengine profile dirs and explicit exit codes; compaction and bash stream suites follow the renamed internals.

tests/test_agent_core.py

@@ -10,6 +10,10 @@ import sys
 
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
+# P0-01：provider 用例经统一配置入口读取临时配置（测试 provider），不碰真实 data/config.json
+from tests._test_env import isolate  # noqa: E402
+isolate("agentcore")
+
 import pytest
 
 from core.agent import (Agent, AgentConfig, AgentError, ModelConfig, RetryConfig)