feat(providers): add Grok 4.6 subscription model

nanobot/cli/provider.py

@@ -29,7 +29,7 @@ _PROVIDER_DISPLAY: dict[str, str] = {
 
 _OAUTH_PROVIDER_DEFAULT_MODELS: dict[str, str] = {
     "openai_codex": "openai-codex/gpt-5.6-sol",
-    "xai_grok": "xai-grok/grok-4.5",
+    "xai_grok": "xai-grok/grok-4.6",
     "github_copilot": "github-copilot/gpt-5.4-mini",
 }
 
@@ -134,7 +134,10 @@ def _set_oauth_provider_as_main(
     config.agents.defaults.model_preset = None
     config.agents.defaults.provider = provider_name
     config.agents.defaults.model = selected_model
-    if provider_name == "xai_grok" and selected_model == "xai-grok/grok-4.5":
+    if provider_name == "xai_grok" and selected_model in {
+        "xai-grok/grok-4.5",
+        "xai-grok/grok-4.6",
+    }:
         config.agents.defaults.context_window_tokens = 500_000
     save_config(config, resolved_config_path)
 

nanobot/providers/registry.py

@@ -461,6 +461,12 @@ PROVIDERS: tuple[ProviderSpec, ...] = (
         display_name="xAI Grok",
         model_catalog="builtin",
         builtin_models=(
+            ProviderModelSpec(
+                id="xai-grok/grok-4.6",
+                label="Grok 4.6",
+                description="Grok via xAI subscription; X Search is enabled when supported.",
+                context_window=500000,
+            ),
             ProviderModelSpec(
                 id="xai-grok/grok-4.5",
                 label="Grok 4.5",

nanobot/providers/xai_grok_provider.py

@@ -35,7 +35,7 @@ from nanobot.providers.xai_oauth import (
 
 DEFAULT_XAI_GROK_URL = "https://cli-chat-proxy.grok.com/v1/responses"
 DEFAULT_XAI_GROK_MODELS_URL = "https://cli-chat-proxy.grok.com/v1/models"
-DEFAULT_XAI_GROK_MODEL = "xai-grok/grok-4.5"
+DEFAULT_XAI_GROK_MODEL = "xai-grok/grok-4.6"
 _MODEL_CAPABILITIES_TTL_S = 5 * 60
 _MAX_ERROR_BODY_CHARS = 1000
 _SENSITIVE_ERROR_KEYS = {