fix(claude): improve backward compatibility for openrouter_compat_mode

Extend backward compatibility support for legacy openrouter_compat_mode field:
- Support number type (1 = enabled, 0 = disabled)
- Support string type ("true"/"1" = enabled)
- Add corresponding test cases for number and string types

src-tauri/src/proxy/providers/claude.rs

@@ -517,6 +517,24 @@ mod tests {
         }));
         assert!(adapter.needs_transform(&legacy_compat_enabled));
 
+        // Backward compatibility: openrouter_compat_mode=1 should enable transform
+        let legacy_compat_enabled_num = create_provider(json!({
+            "env": {
+                "ANTHROPIC_BASE_URL": "https://api.example.com"
+            },
+            "openrouter_compat_mode": 1
+        }));
+        assert!(adapter.needs_transform(&legacy_compat_enabled_num));
+
+        // Backward compatibility: openrouter_compat_mode="true" should enable transform
+        let legacy_compat_enabled_str = create_provider(json!({
+            "env": {
+                "ANTHROPIC_BASE_URL": "https://api.example.com"
+            },
+            "openrouter_compat_mode": "true"
+        }));
+        assert!(adapter.needs_transform(&legacy_compat_enabled_str));
+
         // Backward compatibility: openrouter_compat_mode=false should not enable transform
         let legacy_compat_disabled = create_provider(json!({
             "env": {

src/components/providers/forms/ProviderForm.tsx

@@ -292,9 +292,19 @@ export function ProviderForm({
     try {
       const config = JSON.parse(settingsConfigValue || "{}");
       const format = config?.api_format;
-      if (format === "openai_chat") return "openai_chat";
-      // Backward compatibility: if old openrouter_compat_mode is true, treat as openai_chat
-      if (config?.openrouter_compat_mode === true) return "openai_chat";
+      if (typeof format === "string") {
+        return format === "openai_chat" ? "openai_chat" : "anthropic";
+      }
+
+      // Backward compatibility: old openrouter_compat_mode (bool/number/string)
+      const raw = config?.openrouter_compat_mode;
+      if (typeof raw === "boolean") return raw ? "openai_chat" : "anthropic";
+      if (typeof raw === "number") return raw !== 0 ? "openai_chat" : "anthropic";
+      if (typeof raw === "string") {
+        const normalized = raw.trim().toLowerCase();
+        if (normalized === "true" || normalized === "1") return "openai_chat";
+        return "anthropic";
+      }
     } catch {
       // ignore
     }