resolveModel: accept local/* model ids

runLLMStream in chatTools.ts re-resolved its incoming model via
resolveModel(model, DEFAULT_MAIN_MODEL). resolveModel checked the
hardcoded ALL_MODELS set, which only contained the external
provider catalogue (claude, gemini, openai variants) -- not the
local/* prefix used for Ollama models. So even after chat.ts had
correctly substituted the request body's stale 'gemini-3-flash-preview'
into 'local/llama3.2:3b', runLLMStream's internal resolveModel
silently kicked it BACK to 'gemini-3-flash-preview' (the
DEFAULT_MAIN_MODEL fallback), which then tripped the deepest-layer
self-heal we added in llm/index.ts and produced
"[llm] requested model 'gemini-3-flash-preview' not allowed;
substituting 'local/qwen3-next:80b'" -- not the model the user
actually picked.

The fix is local-aware: treat any id starting with `local/` as a
valid model the caller already validated, so resolveModel passes
it through instead of forcing the gemini fallback.

Also drop the debug trace log from chat.ts now that the cause is
identified.