Revert "security: remove SMTP email notifications"

This reverts commit a1bc8df.

Author: n24q02m

.github/workflows/ci.yml

@@ -134,7 +134,7 @@ jobs:
           fi
 
       - name: PR Agent action step
-        uses: qodo-ai/pr-agent@42d55d4182a4839820b11b6c4d06fce855970301 # main
+        uses: qodo-ai/pr-agent@main
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
@@ -145,3 +145,44 @@ jobs:
           GITHUB_ACTION_CONFIG__AUTO_DESCRIBE: "true"
           GITHUB_ACTION_CONFIG__AUTO_IMPROVE: "true"
           GITHUB_ACTION_CONFIG__HANDLE_PR_ACTIONS: '["opened", "reopened", "ready_for_review", "synchronize"]'
+
+  # ============================================================================
+  # Email Notification (External Contributors)
+  # ============================================================================
+  email-notify:
+    name: Email Notification
+    if: >-
+      (github.event_name == 'issues' || github.event_name == 'pull_request_target')
+      && github.actor != 'n24q02m'
+      && github.event.sender.type != 'Bot'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@fa2e9d605c4eeb9fcad4c99c224cee0c6c7f3594 # v2
+        with:
+          egress-policy: audit
+
+      - name: Send email notification
+        uses: dawidd6/action-send-mail@d38f3f7cd391cdebfe0d38efc3998b935e951c4f # v16
+        with:
+          server_address: smtp.gmail.com
+          server_port: 587
+          username: ${{ secrets.SMTP_USERNAME }}
+          password: ${{ secrets.SMTP_PASSWORD }}
+          subject: >-
+            [${{ github.event.repository.name }}]
+            ${{ github.event_name == 'issues' && 'Issue' || 'PR' }}
+            #${{ github.event.issue.number || github.event.pull_request.number }}:
+            ${{ github.event.issue.title || github.event.pull_request.title }}
+          to: ${{ secrets.NOTIFY_EMAIL }}
+          from: GitHub Notify <${{ secrets.SMTP_USERNAME }}>
+          body: |
+            ${{ github.event_name == 'issues' && 'New issue' || 'New pull request' }} in ${{ github.repository }}
+
+            Title: ${{ github.event.issue.title || github.event.pull_request.title }}
+            Author: ${{ github.actor }}
+            URL: ${{ github.event.issue.html_url || github.event.pull_request.html_url }}
+            Action: ${{ github.event.action }}
+
+            ---
+            ${{ github.event.issue.body || github.event.pull_request.body || 'No description provided.' }}