dx: compact storybook PR comment to single-line header (#9078)

## Summary

Compact the Storybook build status PR comment to a single-line header
with collapsible details, matching the approach from #8677.

## Changes

- **Starting**: Collapsed from multi-line with build steps to `## 🎨
Storybook: ⏳ Building...`
- **Completed (success)**: `## 🎨 Storybook: ✅ Built — [View
Storybook](url)` with timestamp/links in `<details>`
- **Completed (failure)**: `## 🎨 Storybook: ❌ Failed` with details
collapsed
- Removed version-bump branch check (starting comment no longer varies
by branch type)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9078-dx-compact-storybook-PR-comment-to-single-line-header-30f6d73d365081b98666c48a94542b70)
by [Unito](https://www.unito.io)

scripts/cicd/pr-playwright-deploy-and-comment.sh

@@ -2,7 +2,7 @@
 set -e
 
 # Deploy Playwright test reports to Cloudflare Pages and comment on PR
-# Usage: ./pr-playwright-deploy-and-comment.sh <pr_number> <branch_name> <status> [start_time]
+# Usage: ./pr-playwright-deploy-and-comment.sh <pr_number> <branch_name> <status>
 
 # Input validation
 # Validate PR number is numeric
@@ -31,8 +31,6 @@ case "$STATUS" in
         ;;
 esac
 
-START_TIME="${4:-$(date -u '+%m/%d/%Y, %I:%M:%S %p')}"
-
 # Required environment variables
 : "${GITHUB_TOKEN:?GITHUB_TOKEN is required}"
 : "${GITHUB_REPOSITORY:?GITHUB_REPOSITORY is required}"
@@ -135,23 +133,8 @@ post_comment() {
 # Main execution
 if [ "$STATUS" = "starting" ]; then
     # Post concise starting comment
-    comment=$(cat <<EOF
-$COMMENT_MARKER
-## 🎭 Playwright Tests: ⏳ Running...
-
-Tests started at $START_TIME UTC
-
-<details>
-<summary>📊 Browser Tests</summary>
-
-- **chromium**: Running...
-- **chromium-0.5x**: Running...
-- **chromium-2x**: Running...
-- **mobile-chrome**: Running...
-
-</details>
-EOF
-)
+    comment="$COMMENT_MARKER
+## 🎭 Playwright: ⏳ Running..."
     post_comment "$comment"
     
 else
@@ -300,7 +283,7 @@ else
     
     # Generate compact single-line comment
     comment="$COMMENT_MARKER
-**Playwright:** $status_icon $total_passed passed, $total_failed failed$flaky_note"
+## 🎭 Playwright: $status_icon $total_passed passed, $total_failed failed$flaky_note"
 
     # Extract and display failed tests from all browsers (flaky tests are treated as passing)
     if [ $total_failed -gt 0 ]; then