docs(README): 補上 OpenCode server 設定說明

README.md

@@ -74,6 +74,14 @@ jobs:
       issues: write
 ```
 
+OpenAI GPT-5.5 會透過 Responses API 呼叫；設定方式仍使用 `OPENAI_*`：
+
+```yaml
+        OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+        OPENAI_BASE_URL: https://api.openai.com/v1
+        OPENAI_MODEL: gpt-5.5
+```
+
 ### 2. OpenRouter
 ```yaml
 name: AI
@@ -192,7 +200,54 @@ jobs:
       issues: write
 ```
 
-### 6. Ollama
+### 6. OpenCode Server
+```yaml
+name: AI
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref }}
+  cancel-in-progress: true
+on:
+  pull_request:
+    branches-ignore:
+    - master
+    types: [opened, synchronize]
+jobs:
+  code-review:
+    name: Code Review
+    runs-on: ubuntu
+    steps:
+    - name: AI Code Review
+      uses: https://gitea.jsc.idv.tw/actions/code-review@${{ vars.ACTION_CODE_REVIEW_VERSION }}
+      with:
+        GITEA_TOKEN: ${{ secrets.RUNNER_TOKEN }}
+        GITEA_COMMENT_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        OPENCODE_BASE_URL: http://192.168.3.124:4096
+        OPENCODE_PROVIDER: google
+        OPENCODE_MODEL: gemini-2.5-flash
+        # 若 OpenCode server 有設定 OPENCODE_SERVER_PASSWORD，才需要提供：
+        # OPENCODE_SERVER_USERNAME: opencode
+        # OPENCODE_SERVER_PASSWORD: ${{ secrets.OPENCODE_SERVER_PASSWORD }}
+    permissions:
+      contents: write
+      pull-requests: write
+      issues: write
+```
+
+OpenCode Server 串接方式會呼叫 server root 的 `/session` 與 `/session/{sessionID}/message`，並把模型指定為 `providerID=google`、`modelID=gemini-2.5-flash`。可用的內部 OpenCode server：
+
+```yaml
+        OPENCODE_BASE_URL: https://opencode.jsc.idv.me
+```
+
+或：
+
+```yaml
+        OPENCODE_BASE_URL: http://192.168.3.124:4096
+```
+
+OpenCode server 本身必須已設定好 `google` provider 與 `gemini-2.5-flash` model；此 action 不會把 Google API key 傳給 OpenCode server。
+
+### 7. Ollama
 
 ```yaml
 name: AI