Group all JavaScript dependencies into a single Dependabot PR (#164)

Add a groups configuration to the npm ecosystem entry so that all
JS dependency updates are batched into one pull request instead of
creating separate PRs for each package.

https://claude.ai/code/session_01Q8KGCW3XchBEmtA8H6wGAC

Co-authored-by: Claude <noreply@anthropic.com>

Author: kyleconroy

.github/dependabot.yml

@@ -13,3 +13,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+    groups:
+      js-deps:
+        patterns:
+          - "*"