ci: add grouped Dependabot config (npm + github-actions)

Author: asachs01

.github/dependabot.yml

@@ -0,0 +1,24 @@
+version: 2
+updates:
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    open-pull-requests-limit: 10
+    groups:
+      # Bundle all non-major npm updates into a single PR to cut noise.
+      npm-minor-patch:
+        update-types:
+          - "minor"
+          - "patch"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 5
+    groups:
+      github-actions:
+        update-types:
+          - "minor"
+          - "patch"