fix(monitor): specify errors=replace and guard proc.kill in ClusterStatus.refresh in agent_monitor.py

[vaibhavsrv]

Problem

In ods/extensions/services/dashboard-api/agent_monitor.py, ClusterStatus.refresh() decodes stdout from the cluster proxy subprocess using un-parameterized stdout.decode(). If non-UTF-8 characters are returned by status endpoints, stdout.decode() raises an uncaught UnicodeDecodeError. Additionally, calling proc.kill() when sub-processes have already exited could raise ProcessLookupError inside the asyncio.TimeoutError handler.

Fix

Pass errors="replace" to stdout.decode("utf-8", errors="replace") and wrap proc.kill() in a try...except ProcessLookupError: block in ClusterStatus.refresh().

Verification

Verified syntax with python3 -m py_compile ods/extensions/services/dashboard-api/agent_monitor.py. git diff --check passed cleanly.