feat: add monorepo sync notification workflow

Automatically notifies openrouter-web monorepo when changes are pushed to main.
This triggers the subtree sync workflow to create a PR with updates.

Requires MONOREPO_SYNC_TOKEN secret to be configured.

.github/workflows/notify-monorepo.yaml

@@ -0,0 +1,46 @@
+name: Notify Monorepo of Changes
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  notify-monorepo:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Send repository dispatch to monorepo
+        run: |
+          # Determine which event type to send based on repository name
+          REPO_NAME="${GITHUB_REPOSITORY#*/}"  # Gets 'python-sdk' from 'OpenRouterTeam/python-sdk'
+
+          case "$REPO_NAME" in
+            "typescript-sdk")
+              EVENT_TYPE="sync-typescript-sdk"
+              ;;
+            "python-sdk")
+              EVENT_TYPE="sync-python-sdk"
+              ;;
+            "ai-sdk-provider")
+              EVENT_TYPE="sync-ai-sdk-provider"
+              ;;
+            "cli")
+              EVENT_TYPE="sync-cli"
+              ;;
+            *)
+              echo "Unknown repository: $REPO_NAME"
+              exit 1
+              ;;
+          esac
+
+          echo "Sending repository_dispatch event: $EVENT_TYPE"
+
+          curl -L \
+            -X POST \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${{ secrets.MONOREPO_SYNC_TOKEN }}" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/OpenRouterTeam/openrouter-web/dispatches \
+            -d "{\"event_type\":\"$EVENT_TYPE\",\"client_payload\":{\"repository\":\"$GITHUB_REPOSITORY\",\"ref\":\"$GITHUB_REF\",\"sha\":\"$GITHUB_SHA\"}}"
+
+          echo "✅ Notification sent to monorepo"