docs(ci): pass untrusted PR fields via env to prevent script injection (#430)

The CI integration docs interpolated github.event.pull_request.title,
github.base_ref and github.head_ref directly inside shell run: blocks.
GitHub substitutes ${{ }} textually before the shell parses the line, so a
PR title or branch name containing shell metacharacters executes on the
runner of anyone who copies the snippet.

Hoist all three into env: mappings and reference them as shell variables,
matching action.yml:228-244 and the repo's own review rule at
internal/config/rules/rule_docs/github_workflows.md:6.

Applied identically to en, ja and zh; the three code blocks were
byte-identical before and remain so.

pages/src/content/docs/en/integrations/ci.md

@@ -120,24 +120,37 @@ semantic convention like `feat(auth): add OAuth2 support`):
 
 ```yaml
 - name: Run OCR review
+  env:
+    PR_TITLE: ${{ github.event.pull_request.title }}
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review \
-      --background "${{ github.event.pull_request.title }}" \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}" \
+      --background "$PR_TITLE" \
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF" \
       --format json --audience agent
 ```
 
+Pass PR-controlled values through `env:` rather than
+interpolating `${{ }}` directly into `run:`. GitHub substitutes
+`${{ }}` textually *before* the shell parses the line, so a PR
+title or branch name containing shell metacharacters would
+execute on your runner.
+
 #### Custom rules
 
 Pass a project-specific rule file with `--rule`:
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --rule ./my-rules.json \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 See [Review Rules](../../review-rules/) for the schema.
@@ -149,10 +162,13 @@ to stay under your LLM provider's rate limits:
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --concurrency 5 \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 #### Trigger pattern

pages/src/content/docs/ja/integrations/ci.md

@@ -83,24 +83,33 @@ curl -o .github/workflows/ocr-review.yml \
 
 ```yaml
 - name: Run OCR review
+  env:
+    PR_TITLE: ${{ github.event.pull_request.title }}
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review \
-      --background "${{ github.event.pull_request.title }}" \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}" \
+      --background "$PR_TITLE" \
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF" \
       --format json --audience agent
 ```
 
+PR で制御可能な値は `${{ }}` を `run:` に直接展開するのではなく、`env:` 経由で渡してください。GitHub は `${{ }}` を shell が行を解析する *前に* テキストとして置換するため、shell のメタ文字を含む PR タイトルやブランチ名が runner 上で実行されてしまいます。
+
 #### カスタムルール
 
 `--rule` でプロジェクト固有のルールファイルを渡します。
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --rule ./my-rules.json \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 スキーマは[レビュールール](../../review-rules/)を参照してください。
@@ -111,10 +120,13 @@ curl -o .github/workflows/ocr-review.yml \
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --concurrency 5 \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 #### トリガーモード

pages/src/content/docs/zh/integrations/ci.md

@@ -101,24 +101,35 @@ curl -o .github/workflows/ocr-review.yml \
 
 ```yaml
 - name: Run OCR review
+  env:
+    PR_TITLE: ${{ github.event.pull_request.title }}
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review \
-      --background "${{ github.event.pull_request.title }}" \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}" \
+      --background "$PR_TITLE" \
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF" \
       --format json --audience agent
 ```
 
+把 PR 可控的值通过 `env:` 传入，不要把 `${{ }}` 直接插值进 `run:`。GitHub 在
+shell 解析该行 *之前* 就已把 `${{ }}` 做了文本替换，因此包含 shell 元字符的 PR
+标题或分支名会在你的 runner 上被执行。
+
 #### 自定义规则
 
 用 `--rule` 传入项目专属规则文件：
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --rule ./my-rules.json \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 schema 见[评审规则](../../review-rules/)。
@@ -129,10 +140,13 @@ schema 见[评审规则](../../review-rules/)。
 
 ```yaml
 - name: Run OCR review
+  env:
+    BASE_REF: ${{ github.base_ref }}
+    HEAD_REF: ${{ github.head_ref }}
   run: |
     ocr review --concurrency 5 \
-      --from "origin/${{ github.base_ref }}" \
-      --to "origin/${{ github.head_ref }}"
+      --from "origin/$BASE_REF" \
+      --to "origin/$HEAD_REF"
 ```
 
 #### 触发模式