feat: add dependabot and dependabot auto-merge

.github/dependabot.yml

@@ -0,0 +1,41 @@
+version: 2
+
+updates:
+  - package-ecosystem: composer
+    directory: /api
+    schedule:
+      interval: weekly
+    commit-message:
+      prefix: "chore(deps)"
+    pull-request-branch-name:
+      separator: "/"
+    groups:
+      security-patches:
+        patterns:
+          - "*"
+        update-types:
+          - "patch"
+
+  - package-ecosystem: npm
+    directory: /pwa
+    schedule:
+      interval: weekly
+    commit-message:
+      prefix: "chore(deps)"
+    pull-request-branch-name:
+      separator: "/"
+    groups:
+      security-patches:
+        patterns:
+          - "*"
+        update-types:
+          - "patch"
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    commit-message:
+      prefix: "chore(deps)"
+    pull-request-branch-name:
+      separator: "/"

.github/workflows/auto-merge-dependabot.yml

@@ -0,0 +1,31 @@
+name: Auto-merge Dependabot PRs
+
+on:
+  pull_request_target:
+    branches:
+      - main
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login == 'dependabot[bot]' && github.actor == 'dependabot[bot]' && github.event.pull_request.head.repo.full_name == github.repository && !github.event.pull_request.draft
+    steps:
+      - name: Dependabot metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+
+      - name: Auto-merge patch security updates
+        if: |
+          steps.metadata.outputs.update-type == 'patch-update' &&
+          (steps.metadata.outputs.dependency-type == 'direct:production' || 
+           steps.metadata.outputs.dependency-type == 'direct:development')
+        run: gh pr merge --auto --rebase "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}