lk agent dev/console: log level cannot be set via environment variable; console mode has no --log-level flag

[kaushal-aubie]

Describe the bug

With the deprecation of python agent.py console/dev in favor of lk agent dev / lk agent console (per the 1.6.8 release notes, #6656), the new Go-based CLI only supports setting log level via the --log-level flag on lk agent dev. There is no environment variable equivalent (e.g. LIVEKIT_LOG_LEVEL, LOG_LEVEL), which the old Python CLI workflow relied on. This is also tracked as a general feature request in livekit/agents#4340, but it especially affects the new lk agent commands since they are now the recommended entrypoint.

Additionally, lk agent console does not expose a --log-level flag at all (per the CLI docs: https://docs.livekit.io/reference/developer-tools/livekit-cli/agent/#console), so there is currently no supported way to reduce verbosity in console mode.

To Reproduce

1. Run lk agent dev (or lk agent console) in a project.
2. Set LIVEKIT_LOG_LEVEL=info (or similar) in the environment.
3. Observe that DEBUG-level logs are still printed.
4. Attempt to pass --log-level to lk agent console — flag does not exist.

Expected behavior

• lk agent dev should respect a LIVEKIT_LOG_LEVEL (or similar) environment variable, consistent with how deployed agents on LiveKit Cloud already do (per https://docs.livekit.io/deploy/agents/logs/#log-levels).
• lk agent console should support a --log-level flag (or the same environment variable) so verbosity can be controlled locally, matching lk agent dev.

Environment

• lk CLI version: <fill in your lk --version output>
• OS:
• livekit-agents version:

Additional context
Related: livekit/agents#4340 (log level via env var / ServerOptions)