feat(thinking): add adaptive thinking support for Claude models

Add support for Claude's "adaptive" and "auto" thinking modes using `output_config.effort`. Introduce support for new effort level "max" in adaptive thinking. Update thinking logic, validate model capabilities, and extend converters and handling to ensure compatibility with adaptive modes. Adjust static model data with supported levels and refine handling across translators and executors.

internal/thinking/strip.go

@@ -30,7 +30,7 @@ func StripThinkingConfig(body []byte, provider string) []byte {
 	var paths []string
 	switch provider {
 	case "claude":
-		paths = []string{"thinking"}
+		paths = []string{"thinking", "output_config.effort"}
 	case "gemini":
 		paths = []string{"generationConfig.thinkingConfig"}
 	case "gemini-cli", "antigravity":
@@ -59,5 +59,12 @@ func StripThinkingConfig(body []byte, provider string) []byte {
 	for _, path := range paths {
 		result, _ = sjson.DeleteBytes(result, path)
 	}
+
+	// Avoid leaving an empty output_config object for Claude when effort was the only field.
+	if provider == "claude" {
+		if oc := gjson.GetBytes(result, "output_config"); oc.Exists() && oc.IsObject() && len(oc.Map()) == 0 {
+			result, _ = sjson.DeleteBytes(result, "output_config")
+		}
+	}
 	return result
 }