chore: add AI PR Review to github-workflows self-CI

Drops in the same shared workflow we use across the Kotlin/TS service
repos (service-control, service-vehicle, service-api-gateways, etc.)
so PRs to this repo also get an automated AI code review.

Same pattern as service-vehicle and service-api-gateways:
- Triggers on opened, ready_for_review, synchronize, and issue_comment
- Delegates to monta-app/ai-standards/.github/workflows/ai-pr-review.yml@main
- Uses the org-level ANTHROPIC_API_KEY + AI_REVIEWER_SECRET_KEY secrets

Sets run-on-drafts: true so reviews fire on draft PRs as well — useful
for this repo specifically because changes here usually start as drafts
while we test against downstream service repos before promoting.

The actionlint check in pull-request.yml already covers static workflow
syntax; this layers a content/intent review on top, which is useful for
a repo where every change ripples to every Monta service.

Author: JesperTerkelsen

.github/workflows/ai-pr-review.yml

@@ -0,0 +1,16 @@
+name: AI PR Review
+
+on:
+  pull_request:
+    types: [opened, ready_for_review, synchronize]
+  issue_comment:
+    types: [created]
+
+jobs:
+  ai-review:
+    uses: monta-app/ai-standards/.github/workflows/ai-pr-review.yml@main
+    with:
+      run-on-drafts: true
+    secrets:
+      ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
+      AI_REVIEWER_SECRET_KEY: ${{ secrets.AI_REVIEWER_SECRET_KEY }}