fix(workbuddy): keep advertised max reasoning effort

changelog/unreleased/workbuddy-max-effort.md

@@ -0,0 +1,7 @@
+### English
+
+- WorkBuddy no longer silently downgrades `max` reasoning effort to `xhigh` when the model catalog advertises `max`.
+
+### 中文
+
+- WorkBuddy 在模型目录声明支持 `max` 时，不再把 `max` 推理档位静默降级为 `xhigh`。

internal/providers/workbuddy/mapping.go

@@ -88,9 +88,6 @@ func applyChatReasoning(obj map[string]any, req translate.ChatRequest, storedLev
 			return ""
 		}
 	}
-	if level == "max" {
-		level = "xhigh"
-	}
 	if usesTopLevelReasoningFields(req.Model) {
 		delete(obj, "reasoning")
 		obj["reasoning_effort"] = level

internal/providers/workbuddy/mapping_test.go

@@ -61,3 +61,25 @@ func TestApplyChatReasoningDeepseekUsesCatalogDefault(t *testing.T) {
 		t.Fatalf("default effort=%v", obj["reasoning_effort"])
 	}
 }
+
+// Regression for #321: a catalog that advertises "max" receives "max"
+// upstream instead of a silent downgrade to "xhigh".
+func TestApplyChatReasoningKeepsAdvertisedMax(t *testing.T) {
+	caps := providers.ModelCapabilities{
+		ReasoningOptions: []string{"low", "high", "max"},
+		ReasoningDefault: "max",
+	}
+	obj := map[string]any{}
+	if got := applyChatReasoning(obj, translate.ChatRequest{Model: "glm-5.3", ReasoningEffort: json.RawMessage(`"max"`)}, "", caps); got != "max" {
+		t.Fatalf("resolved level=%q", got)
+	}
+	reasoning, _ := obj["reasoning"].(map[string]any)
+	if reasoning["effort"] != "max" {
+		t.Fatalf("reasoning=%v", obj["reasoning"])
+	}
+	obj = map[string]any{}
+	applyChatReasoning(obj, translate.ChatRequest{Model: "deepseek-v4-pro", ReasoningEffort: json.RawMessage(`"max"`)}, "", caps)
+	if obj["reasoning_effort"] != "max" {
+		t.Fatalf("top-level reasoning_effort=%v", obj["reasoning_effort"])
+	}
+}