fix(tokenlab): list the provider in Add Model and use the shared base-url lookup

TokenLab gets an entry in provider_create_fields.json, which the Add Model
dropdown test requires for every backend provider. The explicit endpoint
branch in get_llm_provider is removed: JSONProviderRegistry.get_by_base_url
already resolves a JSON-configured provider from its base url, and the
removed branch declared a Final inside the loop, which the type gate counts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

litellm/litellm_core_utils/get_llm_provider_logic.py

@@ -389,10 +389,6 @@ def get_llm_provider(
                     elif endpoint == "https://api.inference.wandb.ai/v1":
                         custom_llm_provider = "wandb"
                         dynamic_api_key = get_secret_str("WANDB_API_KEY")
-                    elif endpoint == "https://api.tokenlab.sh/v1":
-                        custom_llm_provider = "tokenlab"
-                        tokenlab_config: Final = JSONProviderRegistry.get("tokenlab")
-                        dynamic_api_key = get_secret_str(tokenlab_config.api_key_env) if tokenlab_config else None
                     elif endpoint == "https://pinstripes.io/v1":
                         custom_llm_provider = "pinstripes"
                         dynamic_api_key = get_secret_str("PINSTRIPES_API_KEY")

litellm/proxy/public_endpoints/provider_create_fields.json

@@ -3207,6 +3207,34 @@
     ],
     "default_model_placeholder": "gpt-3.5-turbo"
   },
+  {
+    "provider": "TOKENLAB",
+    "provider_display_name": "TokenLab",
+    "litellm_provider": "tokenlab",
+    "credential_fields": [
+      {
+        "key": "api_base",
+        "label": "API Base",
+        "placeholder": "https://api.tokenlab.sh/v1",
+        "tooltip": null,
+        "required": false,
+        "field_type": "text",
+        "options": null,
+        "default_value": null
+      },
+      {
+        "key": "api_key",
+        "label": "API Key",
+        "placeholder": null,
+        "tooltip": null,
+        "required": true,
+        "field_type": "password",
+        "options": null,
+        "default_value": null
+      }
+    ],
+    "default_model_placeholder": "tokenlab/gpt-5.5"
+  },
   {
     "provider": "TOPAZ",
     "provider_display_name": "Topaz",