feat: 更新代理模型配置为 gemini-3-flash 和 claude-sonnet-4-5

- 将多个代理的模型配置更新为使用 gemini-3-flash 和 claude-sonnet-4-5，以提升性能和响应效率。

oh-my-opencode.jsonc

@@ -2,7 +2,7 @@
   "$schema": "https://raw.githubusercontent.com/code-yeongyu/oh-my-opencode/master/assets/oh-my-opencode.schema.json",
   "agents": {
     "Sisyphus": {
-      "model": "anthropic-gateway/claude-opus-4-5-thinking"
+      "model": "anthropic-gateway/claude-sonnet-4-5"
     },
     "Planner-Sisyphus": {
       "model": "anthropic-gateway/claude-opus-4-5-thinking"
@@ -14,10 +14,10 @@
       "model": "google-gateway/gemini-3-pro-high"
     },
     "librarian": {
-      "model": "glm-coding-plan/glm-4.7"
+      "model": "google-gateway/gemini-3-flash"
     },
     "explore": {
-      "model": "opencode/grok-code"
+      "model": "google-gateway/gemini-3-flash"
     },
     "document-writer": {
       "model": "google-gateway/gemini-3-flash"