GLM output was garbage: colibri keeps only EOS as a hard stop in serve mode (it filters
the non-EOS special-token stops for tool-call safety, #401), so the model ran past its
turn and emitted <|user|>/<think>/</think> and repeated the prompt.

- backend: clean_glm_output cuts the reply at the first turn marker (<|user|>,
  <|observation|>, <|assistant|>, <|system|>, <|endoftext|>) and strips control tokens
  (<think>,</think>,[gMASK],<sop>). Applied to both non-stream and stream paths; the
  stream holds back a short tail so a marker split across chunks never leaks.
- Early stop: generate paths pass a `cancelled` hook that fires the moment a turn
  marker appears, so colibri CANCELs instead of decoding to max_tokens — a big saving
  at streaming-bound decode speeds. MuxEngine.run now treats our own CANCELLED ack as a
  clean early stop (returns partial stats) instead of raising.
- alias: _resolve_container now resolves the configured colibri model_id (e.g.
  glm-5.2-colibri) and colibri.model_path to the container, not only the full repo path
  — so `{"model":"glm-5.2-colibri"}` loads instead of "no container resolved".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LoSpEthysqmseCc6Geizty