chore: 更新 provider 与代理模型映射

将部分代理模型切换到 litellm、Gemini 和 Sonnet 配置，以统一接入方式并匹配新的模型来源。

oh-my-opencode.jsonc

@@ -4,13 +4,13 @@
     "sisyphus": { "model": "anthropic/claude-opus-4-6", "variant": "max" },
     "hephaestus": { "model": "openai/gpt-5.3-codex", "variant": "medium" },
     "oracle": { "model": "openai/gpt-5.2", "variant": "high" },
-    "librarian": { "model": "bailian-coding-plan/MiniMax-M2.5" },
-    "explore": { "model": "bailian-coding-plan/MiniMax-M2.5" },
-    "multimodal-looker": { "model": "bailian-coding-plan/kimi-k2.5" },
+    "librarian": { "model": "google/gemini-3-flash-preview" },
+    "explore": { "model": "litellm/grok-code-fast-1" },
+    "multimodal-looker": { "model": "openai/gpt-5.3-codex", "variant": "medium" },
     "prometheus": { "model": "anthropic/claude-opus-4-6", "variant": "max" },
     "metis": { "model": "anthropic/claude-opus-4-6", "variant": "max" },
     "momus": { "model": "openai/gpt-5.2", "variant": "medium" },
-    "atlas": { "model": "bailian-coding-plan/kimi-k2.5" }
+    "atlas": { "model": "anthropic/claude-sonnet-4-6" }
   },
   "categories": {
     "visual-engineering": { "model": "google/gemini-3.1-pro-preview", "variant": "high" },
@@ -20,7 +20,7 @@
     "quick": { "model": "anthropic/claude-haiku-4-5" },
     "unspecified-low": { "model": "anthropic/claude-sonnet-4-6" },
     "unspecified-high": { "model": "anthropic/claude-opus-4-6", "variant": "max" },
-    "writing": { "model": "bailian-coding-plan/kimi-k2.5" }
+    "writing": { "model": "google/gemini-3-flash" }
   },
   "git_master": {
     "commit_footer": false,

opencode.jsonc

@@ -78,14 +78,21 @@
         }
       }
     },
-    "bailian-coding-plan": {
-      "npm": "@ai-sdk/anthropic",
-      "name": "Model Studio Coding Plan",
+    "litellm": {
+      "npm": "@ai-sdk/openai",
       "options": {
-        "baseURL": "https://coding.dashscope.aliyuncs.com/apps/anthropic/v1",
-        "apiKey": "{env:BAILIAN_API_KEY}"
+        "baseURL": "{env:LITELLM_BASE_URL}/v1",
+        "apiKey": "{env:LITELLM_API_KEY}"
       },
       "models": {
+        // Grok
+        "grok-code-fast-1": {
+          "name": "Grok Code Fast 1",
+          "reasoning": true,
+          "modalities": { "input": ["text"], "output": ["text"] },
+          "limit": { "context": 256000, "output": 10000 }
+        },
+
         // GLM
         "glm-5": {
           "name": "GLM-5",