[Bug]: Agents and Channels commands emit plain-text errors in `--json` mode

[aaaajanus2016]

OpenSquilla version or commit

0.5.4

Area

CLI

Reproduction steps

opensquilla agents delete qa-does-not-exist --force --json
opensquilla channels describe qa-does-not-exist --json

Use sessions show as a control:

opensquilla sessions show agent:main:webchat:does-not-exist --json

Expected behavior

When --json is requested, every success and failure path should emit one valid JSON document with a stable error code/message and no human renderer output.

Actual behavior

The first two commands exit 2 but emit plain text:

Error: 'Agent "qa-does-not-exist" not found'
Error: "unknown channel type: 'qa-does-not-exist'"

The control command exits 2 with structured JSON:

{"error":{"message":"'Session not found: ...'","code":"NOT_FOUND"}}

Environment

windows 11

Diagnostic bundle and error reference

No response