feat(xai): default to grok-build-0.1

Switch the default model for the xAI/Grok provider and the xAI web
search backend from grok-4.3 to grok-build-0.1. grok-build-0.1 is
already recognized by the model metadata, so no new model definition
is required; grok-4.3 remains selectable.

hermes_cli/model_setup_flows.py

@@ -517,7 +517,7 @@ def _model_flow_xai_oauth(_config, current_model="", *, args=None):
         pass
 
     models = list(_PROVIDER_MODELS.get("xai-oauth") or _PROVIDER_MODELS.get("xai") or [])
-    selected = _prompt_model_selection(models, current_model=current_model or (models[0] if models else "grok-4.3"))
+    selected = _prompt_model_selection(models, current_model=current_model or (models[0] if models else "grok-build-0.1"))
     if selected:
         _save_model_choice(selected)
         _update_config_for_provider("xai-oauth", base_url)

hermes_cli/models.py

@@ -110,6 +110,7 @@ def _codex_curated_models() -> list[str]:
 # (grok-4, grok-4-0709, grok-4-fast{,-reasoning,-non-reasoning},
 #  grok-4-1-fast{,-reasoning,-non-reasoning}, grok-code-fast-1 → grok-4.3).
 _XAI_STATIC_FALLBACK: list[str] = [
+    "grok-build-0.1",
     "grok-4.3",
     "grok-4.20-0309-reasoning",
     "grok-4.20-0309-non-reasoning",
@@ -117,7 +118,7 @@ _XAI_STATIC_FALLBACK: list[str] = [
 ]
 
 
-_XAI_TOP_MODEL = "grok-4.3"
+_XAI_TOP_MODEL = "grok-build-0.1"
 
 
 def _xai_promote_top(ids: list[str]) -> list[str]:

plugins/web/xai/provider.py

@@ -46,7 +46,7 @@ from tools.xai_http import (
 
 logger = logging.getLogger(__name__)
 
-DEFAULT_MODEL = "grok-4.3"
+DEFAULT_MODEL = "grok-build-0.1"
 DEFAULT_TIMEOUT = 90
 _MAX_DOMAIN_FILTERS = 5  # xAI hard cap on allowed_domains / excluded_domains