Add dependency maintenance automation

.github/dependabot.yml

@@ -0,0 +1,22 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 5
+    groups:
+      dev-dependencies:
+        dependency-type: "development"
+        patterns:
+          - "*"
+    ignore:
+      - dependency-name: "obsidian"
+        update-types:
+          - "version-update:semver-minor"
+          - "version-update:semver-major"

.github/workflows/check.yml

@@ -0,0 +1,31 @@
+name: Check
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    name: npm run check
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Check
+        run: npm run check