ci(digest): run CI on push to ci/upstream-digest branch (#53)

Problem: GITHUB_TOKEN-created PRs suppress pull_request triggers,
so CI never runs and auto-merge stalls.

Solution: add ci/upstream-digest to the push trigger in test and
quality workflows. CI runs on the branch push before the PR exists;
check results attach to the commit SHA so the PR sees them as
passing. The digest workflow reverts to GITHUB_TOKEN for PR
creation — no PAT needed, no contribution inflation.

.github/workflows/quality.yaml

@@ -5,7 +5,7 @@ on:
   pull_request:
     branches: [main]
   push:
-    branches: [main]
+    branches: [main, ci/upstream-digest]
 
 jobs:
   changes:

.github/workflows/test.yaml

@@ -4,7 +4,7 @@ on:
   pull_request:
     branches: [main]
   push:
-    branches: [main]
+    branches: [main, ci/upstream-digest]
 
 jobs:
   test:

.github/workflows/upstream-digest.yml

@@ -38,7 +38,7 @@ jobs:
           git commit -m "docs(upstream): upstream digest $(date +%Y-%m-%d)"
           git push --force origin "${BRANCH}"
           if ! gh pr list --head "${BRANCH}" --state open --json number --jq '.[0].number' | grep -q .; then
-            PR_URL=$(GH_TOKEN="${{ secrets.DIGEST_PAT }}" gh pr create \
+            PR_URL=$(gh pr create \
               --title "docs(upstream): upstream digest" \
               --body "Automated weekly digest of new upstream activity. Triage by updating statuses and notes." \
               --base main \