Update Longcat presets to LongCat-2.0 (#4838)

* Update Longcat presets to LongCat-2.0

* fix(proxy): classify LongCat-2.0 as text-only for media sanitizer

The Longcat presets now use LongCat-2.0, but the known_text_only_model
allowlist still only matched the retired longcat-flash-chat tail. Without
this, images pasted into a text-only LongCat-2.0 session are forwarded
upstream instead of being replaced with the unsupported-image marker,
causing a hard rejection. Add longcat-2.0 (keeping the retired name for
saved configs) and a regression test.

---------

Co-authored-by: chengzifeng <chengzifeng@meituan.com>
Co-authored-by: Jason <farion1231@gmail.com>

src/config/opencodeProviderPresets.ts

@@ -1054,12 +1054,15 @@ export const opencodeProviderPresets: OpenCodeProviderPreset[] = [
       npm: "@ai-sdk/openai-compatible",
       name: "Longcat",
       options: {
-        baseURL: "https://api.longcat.chat/v1",
+        baseURL: "https://api.longcat.chat/openai/v1",
         apiKey: "",
         setCacheKey: true,
       },
       models: {
-        "LongCat-Flash-Chat": { name: "LongCat Flash Chat" },
+        "LongCat-2.0": {
+          name: "LongCat 2.0",
+          options: { thinking: { type: "disabled" } },
+        },
       },
     },
     category: "cn_official",
@@ -1068,8 +1071,8 @@ export const opencodeProviderPresets: OpenCodeProviderPreset[] = [
     templateValues: {
       baseURL: {
         label: "Base URL",
-        placeholder: "https://api.longcat.chat/v1",
-        defaultValue: "https://api.longcat.chat/v1",
+        placeholder: "https://api.longcat.chat/openai/v1",
+        defaultValue: "https://api.longcat.chat/openai/v1",
         editorValue: "",
       },
       apiKey: {