Group Dependabot updates to reduce PR noise

[humanbydefinition]

Groups minor and patch Dependabot updates so a weekly run produces a few grouped PRs instead of one PR per dependency. Major updates stay ungrouped for individual review.

groups:
  npm-development:
    dependency-type: development
    update-types: [minor, patch]
  npm-production:
    dependency-type: production
    update-types: [minor, patch]

Before	After
One PR per dependency per week	Up to three grouped PRs per week (npm dev, npm prod, actions)