ModelNameCompleter crashes with AttributeError when no model is configured (get_active_model() returns None)

Problem

ModelNameCompleter.get_completions() in code_puppy/command_line/model_picker_completion.py:73-118 crashes the prompt completion when no model is configured:

active_model_name = get_active_model()           # line 104 — can return None
if model_name.lower() == active_model_name.lower():   # AttributeError on None

get_active_model() delegates to get_global_model_name() (config.py:604), whose docstring explicitly states it returns None if unset (fresh install before /add_model, or an invalid configured model with an empty merged config). The first time the user types /model to fix that situation, the completer raises AttributeError: 'NoneType' object has no attribute 'lower' inside prompt_toolkit's completion thread.

Two adjacent smells in the same method:

• active_model_name = get_active_model() is re-evaluated inside the per-model loop (once per model in the catalog) even though it cannot change during one completion pass — hoist it above the for.
• self.model_names = load_model_names() is captured once in __init__ (line 70), so models added via /add_model mid-session never appear in completions until restart, while the description lookup is live via _load_models_config() — inconsistent freshness.

Suggested fix

active_model_name = (get_active_model() or "").lower()
for model_name in load_model_names():   # or refresh self.model_names per call
    ...
    if model_name.lower() == active_model_name:

Filed by Zen Reviewer C (code-puppy-60635a)

Read ModelNameCompleter.get_completions() in code_puppy/command_line/model_picker_completion.py:73-118 and the None behavior documented around get_global_model_name() in config.py:604. Verify /model completion with no configured model and after /add_model; done means completion no longer crashes and newly added models appear without restarting.