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-tauri/src/codex_config.rs

@@ -2610,7 +2610,7 @@ web_search = "disabled"
         for (model, host) in [
             ("mimo-v2.5-pro", "https://api.xiaomimimo.com/v1"),
             ("mimo-v2.5", "https://token-plan-cn.xiaomimimo.com/v1"),
-            ("LongCat-2.0-Preview", "https://api.longcat.chat/openai/v1"),
+            ("LongCat-2.0", "https://api.longcat.chat/openai/v1"),
             ("MiniMax-M3", "https://api.minimax.io/v1"),
             ("MiniMax-M3", "https://api.minimaxi.com/v1"),
         ] {