feat: add nightly branch workflow

docs/plans/pr-434-docker-analysis.md

@@ -12,6 +12,7 @@
 **PR Status:** ✅ ALL CHECKS PASSING - No remediation needed
 
 PR #434: `feat: add API-Friendly security header preset for mobile apps`
+
 - **Branch:** `feature/beta-release`
 - **Latest Commit:** `99f01608d986f93286ab0ff9f06491c4b599421c`
 - **Overall Status:** ✅ 23 successful checks, 3 skipped, 0 failing, 0 cancelled
@@ -28,7 +29,7 @@ The 3 "CANCELLED" statuses reported were caused by GitHub Actions' concurrency m
 
 **No remediation required.** The PR is healthy with all required checks passing. The "failing" Docker tests are actually cancelled runs from GitHub Actions' concurrency management, which is working as designed to save resources.
 
-### Key Takeaways:
+### Key Takeaways
 
 1. ✅ All 23 required checks passing
 2. ✅ Docker build completed successfully
@@ -36,7 +37,7 @@ The 3 "CANCELLED" statuses reported were caused by GitHub Actions' concurrency m
 4. ℹ️ CANCELLED = superseded runs (expected)
 5. ℹ️ NEUTRAL Trivy = skipped for PRs (expected)
 
-### Next Steps:
+### Next Steps
 
 **Immediate:** None - PR is ready for review and merge