ci: add npm Dependabot ecosystem and Dependabot auto-merge

Adds an npm ecosystem entry for packages/katana-client (the package-lock.json
CI gates with `npm ci`), closing the TypeScript client's dependency-update gap.

Adds dependabot-auto-merge.yml: enables GitHub native auto-merge on patch/minor
Dependabot PRs via dependabot/fetch-metadata + `gh pr merge --auto --squash`.
Major bumps are left for human review. Requires "Allow auto-merge" and branch
protection with required checks (auto-merge waits for green; never bypasses).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dougborg

.github/dependabot.yml

@@ -4,6 +4,8 @@
 #
 # Supported ecosystems:
 # - uv: Python dependencies via pyproject.toml and uv.lock (GA since March 2025)
+# - npm: TypeScript client deps via packages/katana-client/package-lock.json
+#        (the lockfile CI gates with `npm ci` in the typescript-client job)
 # - github-actions: Workflow action versions
 # - docker: Base images in Dockerfiles
 #
@@ -36,6 +38,31 @@ updates:
       prefix: "chore(deps)"
       include: "scope"
 
+  # TypeScript client (npm — packages/katana-client/package-lock.json)
+  # This is the lockfile CI installs from (`npm ci` in the typescript-client job).
+  # The root pnpm workspace lockfile is not gated by CI, so it's intentionally
+  # not tracked here to avoid churning a lockfile nothing verifies.
+  - package-ecosystem: "npm"
+    directory: "/packages/katana-client"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+      time: "09:00"
+      timezone: "UTC"
+    open-pull-requests-limit: 10
+    labels:
+      - "dependencies"
+      - "typescript"
+    groups:
+      # Group minor/patch updates to reduce PR noise
+      npm-minor-patch:
+        update-types:
+          - "minor"
+          - "patch"
+    commit-message:
+      prefix: "chore(deps)"
+      include: "scope"
+
   # GitHub Actions
   - package-ecosystem: "github-actions"
     directory: "/"

.github/workflows/README.md

@@ -123,6 +123,25 @@ See
 [Automated Dependency Management](../../docs/MONOREPO_SEMANTIC_RELEASE.md#automated-dependency-management)
 for details.
 
+### [dependabot-auto-merge.yml](dependabot-auto-merge.yml)
+
+**Trigger:** `pull_request_target` on Dependabot PRs
+
+**Purpose:** Enable GitHub native auto-merge on low-risk Dependabot PRs so they merge
+once required CI checks pass
+
+**Steps:**
+
+- Read update metadata via `dependabot/fetch-metadata`
+- For patch/minor updates, run `gh pr merge --auto --squash`
+- Major version bumps are skipped and left for human review
+
+**Permissions:** `contents: write`, `pull-requests: write`
+
+**Requires:** "Allow auto-merge" enabled in repo settings, and branch protection on
+`main` with required status checks (auto-merge waits for green; it never bypasses a
+failing check).
+
 ### [copilot-setup-steps.yml](copilot-setup-steps.yml)
 
 **Type:** Reusable workflow

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

@@ -0,0 +1,37 @@
+name: Dependabot auto-merge
+
+# Enable GitHub's native auto-merge on low-risk Dependabot PRs so they merge
+# themselves once required CI checks pass. Branch protection still gates the
+# merge — this only flips the "auto-merge when green" switch; it never bypasses
+# a failing check. Major version bumps are intentionally left for human review.
+#
+# Requires:
+#   - "Allow auto-merge" enabled in repo settings (Settings → General).
+#   - Branch protection on `main` with required status checks, so a PR cannot
+#     merge until CI is green.
+
+on: pull_request_target
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    runs-on: ubuntu-latest
+    # Only act on PRs opened by Dependabot.
+    if: github.actor == 'dependabot[bot]'
+    steps:
+      - name: Fetch Dependabot metadata
+        id: meta
+        uses: dependabot/fetch-metadata@v2
+
+      - name: Enable auto-merge for patch and minor updates
+        # update-type is semver-major / semver-minor / semver-patch. Auto-merge
+        # everything except majors. Grouped PRs report the highest bump in the
+        # group, so a group containing a major is treated as a major and skipped.
+        if: steps.meta.outputs.update-type != 'version-update:semver-major'
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}