* fix(agents): keep host paths out of agent and user-profile error details
The custom-agent and user-profile routes put str(e) in their 500
detail. Agent config parse errors and filesystem OSErrors name the
absolute host path under users/<user_id>/, so a caller saw it in the
response. Return the fixed "Failed to <action>" detail the import and
export routes already use and keep the full error in the existing log
lines. PUT also handles a parse error from its initial config load.
The scheduled-task assistant resolver echoed the same parse error as
its invalid_assistant 422 message, which reached the UI and the
scheduler tool result. It now logs the error and returns a fixed
message under the same code.
* docs(changelog): reference #7255 for the agents error detail fix
c5306142db