ci: add GitHub App auth and downstream repo triggers

Switches from GITHUB_TOKEN to GitHub App authentication to enable triggering workflows in downstream repositories. After updating price data, sends repository_dispatch events to indexers and accounting repos to trigger dependency updates.

Author: PaulRBerg

.github/workflows/update-price-data.yml

@@ -11,8 +11,15 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v5
+
+      - name: Get app installation token
+        id: app-token
+        uses: actions/create-github-app-token@v2
         with:
-          persist-credentials: true
+          app-id: ${{ vars.APP_ID }}
+          owner: ${{ github.repository_owner }}
+          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+          repositories: price-data,indexers,accounting
 
       - name: Set up devkit
         uses: sablier-labs/devkit/actions/setup@main
@@ -31,7 +38,7 @@ jobs:
         run: just fetch-forex
 
       - name: Verify changes
-        run: |
+        run: | #shell
           if ! git diff --quiet -- crypto/ forex/; then
             echo "✅ TSV files were updated"
             exit 0
@@ -45,16 +52,35 @@ jobs:
         run: echo "human=$(date '+%B %d, %Y at %H:%M UTC')" >> $GITHUB_OUTPUT
 
       - name: Commit and push changes
-        run: |
+        env:
+          GH_TOKEN: ${{ steps.app-token.outputs.token }}
+        run: | #shell
           git config --local user.email "github-actions[bot]@users.noreply.github.com"
           git config --local user.name "github-actions[bot]"
+          git remote set-url origin https://x-access-token:${GH_TOKEN}@github.com/${{ github.repository }}.git
           git add crypto/ forex/
           git commit -m "chore: update price data - ${{ steps.timestamp.outputs.human }}"
           git push
 
+      - name: Trigger downstream updates
+        env:
+          GH_TOKEN: ${{ steps.app-token.outputs.token }}
+        run: | #shell
+          gh api repos/sablier-labs/indexers/dispatches \
+            -f event_type=price-data-updated \
+            -f client_payload[timestamp]="${{ steps.timestamp.outputs.human }}"
+
+          gh api repos/sablier-labs/accounting/dispatches \
+            -f event_type=price-data-updated \
+            -f client_payload[timestamp]="${{ steps.timestamp.outputs.human }}"
+
       - name: Add summary
-        run: |
+        run: | #shell
           echo "## Update result" >> $GITHUB_STEP_SUMMARY
           echo "✅ Passed" >> $GITHUB_STEP_SUMMARY
           echo "" >> $GITHUB_STEP_SUMMARY
           echo "Updated price data at ${{ steps.timestamp.outputs.human }}" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "Triggered updates in:" >> $GITHUB_STEP_SUMMARY
+          echo "- sablier-labs/indexers" >> $GITHUB_STEP_SUMMARY
+          echo "- sablier-labs/accounting" >> $GITHUB_STEP_SUMMARY