fix(codex): oauth 改回經 inputs.oauth 傳入

composite action 讀不到 secrets context，改回由呼叫端以 with: oauth:
${{ secrets.CODEX_OAUTH }} 經 inputs.oauth 傳入；action 從 inputs.oauth
讀取並保留空值把關，移除 job 層 CODEX_OAUTH env。

.gitea/workflows/ci.yaml

@@ -23,11 +23,10 @@ jobs:
     name: Codex
     runs-on: ubuntu
     needs: release-tag-version
-    env:
-      CODEX_OAUTH: ${{ secrets.CODEX_OAUTH }}
     steps:
     - name: 測試工具
       id: codex
       uses: https://gitea.jsc.idv.tw/composite-actions/codex@v${{ needs.release-tag-version.outputs.version }}
       with:
+        oauth: ${{ secrets.CODEX_OAUTH }}
         prompt: "請自我介紹"

action.yml

@@ -6,6 +6,9 @@ inputs:
     description: '傳給 Codex CLI 的提示詞'
     required: false
     default: "請自我介紹"
+  oauth:
+    description: 'base64 編碼的 Codex OAuth token 檔案內容'
+    required: true
 outputs:
   text:
     description: '輸出的文字'
@@ -14,9 +17,11 @@ runs:
   using: 'composite'
   steps:
   - name: 安裝工具
+    env:
+      OAUTH: ${{ inputs.oauth }}
     run: |
-      if [ -z "$CODEX_OAUTH" ]; then
-        echo 'CODEX_OAUTH environment variable is required (set it from secrets.CODEX_OAUTH in the caller workflow).' >&2
+      if [ -z "$OAUTH" ]; then
+        echo 'oauth input (secrets.CODEX_OAUTH) is required and must not be empty.' >&2
         exit 1
       fi
 
@@ -24,7 +29,7 @@ runs:
 
       oauth_file="$HOME/.codex/auth.json"
       install -d -m 700 "$(dirname "$oauth_file")"
-      printf '%s' "$CODEX_OAUTH" | base64 -d > "$oauth_file"
+      printf '%s' "$OAUTH" | base64 -d > "$oauth_file"
       chmod 600 "$oauth_file"
     shell: bash
   - name: 執行工具