feat(/review): support pull_request_review & pull_request_review_comment events (#161)

### Overview
This adds support for invoking `@gemini-cli /review` in
`pull_request_review` & `pull_request_review_comment` events.

### Testing
   1. Test the `pull_request_review_comment` trigger:
       * Went to the "Files changed" tab of a pull request.
       * Added a comment on a line of code.
       * Use the phrase `@gemini-cli /review (single comment)`
       * Submitted the comment.

   2. Test the `pull_request_review` trigger:
       * Went to the "Files changed" tab of a pull request.
       * Clicked the "Review changes" button in the top right.
       * Used the phrase `@gemini-cli /review (review changes comment)`
       * Selected "Comment" and submitted the review.

Fixes #150

Author: leehagoodjames

.github/workflows/gemini-pr-review.yml

@@ -109,14 +109,14 @@ jobs:
           } >> "${GITHUB_OUTPUT}"
 
 
-      - name: 'Get PR details (issue_comment)'
+      - name: 'Get PR details (issue_comment & reviews)'
         id: 'get_pr_comment'
         if: |-
-          ${{ github.event_name == 'issue_comment' }}
+          ${{ github.event_name == 'issue_comment' || github.event_name == 'pull_request_review' || github.event_name == 'pull_request_review_comment' }}
         env:
           GITHUB_TOKEN: '${{ steps.generate_token.outputs.token || secrets.GITHUB_TOKEN }}'
-          COMMENT_BODY: '${{ github.event.comment.body }}'
-          PR_NUMBER: '${{ github.event.issue.number }}'
+          COMMENT_BODY: '${{ github.event.comment.body || github.event.review.body }}'
+          PR_NUMBER: '${{ github.event.issue.number || github.event.pull_request.number }}'
         run: |-
           set -euo pipefail
 

examples/workflows/pr-review/gemini-pr-review.yml

@@ -109,14 +109,14 @@ jobs:
           } >> "${GITHUB_OUTPUT}"
 
 
-      - name: 'Get PR details (issue_comment)'
+      - name: 'Get PR details (issue_comment & reviews)'
         id: 'get_pr_comment'
         if: |-
-          ${{ github.event_name == 'issue_comment' }}
+          ${{ github.event_name == 'issue_comment' || github.event_name == 'pull_request_review' || github.event_name == 'pull_request_review_comment' }}
         env:
           GITHUB_TOKEN: '${{ steps.generate_token.outputs.token || secrets.GITHUB_TOKEN }}'
-          COMMENT_BODY: '${{ github.event.comment.body }}'
-          PR_NUMBER: '${{ github.event.issue.number }}'
+          COMMENT_BODY: '${{ github.event.comment.body || github.event.review.body }}'
+          PR_NUMBER: '${{ github.event.issue.number || github.event.pull_request.number }}'
         run: |-
           set -euo pipefail