providers: add teamorouter; pick the first /models id when no default model

src/models.c

@@ -11,6 +11,9 @@ static const cst_provider_t PROVIDERS[] = {
     {"deepseek", "https://api.deepseek.com/v1", "deepseek-flash",
      "DEEPSEEK_API_KEY"},
     {"openai", "https://api.openai.com/v1", "gpt-4.1-mini", "OPENAI_API_KEY"},
+    /* Router: no fixed model; the first id from GET /models is picked. */
+    {"teamorouter", "https://api.teamorouter.com/v1", "",
+     "TEAMOROUTER_API_KEY"},
 };
 
 const cst_provider_t *cst_provider_find(const char *name) {
@@ -102,6 +105,10 @@ long cst_model_context_tokens(const char *model) {
            {"o3", 200000},       {"o4", 200000},      {"claude", 200000},
            {"qwen", 131072},     {"glm", 128000},     {"kimi", 131072}};
   if (model) {
+    /* routers name models "vendor/model" */
+    const char *slash = strrchr(model, '/');
+    if (slash && slash[1])
+      model = slash + 1;
     for (size_t i = 0; i < sizeof(T) / sizeof(T[0]); i++) {
       if (strncmp(model, T[i].prefix, strlen(T[i].prefix)) == 0)
         return T[i].tokens;