feat(docs): tier 2 — dashboard view and save-modal tutorial screenshots

[rusackas]

SUMMARY

Tier 2 of the living docs:screenshots system (stacked on #39444). Adds five Playwright-generated screenshots from the Creating your first dashboard tutorial:

Output path	What it shows
tutorial_first_dashboard.png	Sales Dashboard content (view mode)
publish_button_dashboard.png	Dashboard header with Published badge, Edit button
tutorial_edit_button.png	Isolated Edit dashboard button
tutorial_chart_resize.png	Dashboard in edit mode with side panel
tutorial_save_slice.png	Save chart modal from explore

Refactors the existing dashboard screenshot test to share an openSalesDashboard helper with the three new dashboard-based tests.

Removes the five captured entries from screenshot-manifest.yaml (tutorial count 42 → 37).

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

The five updated images in docs/static/img/tutorial/ are the before/after.

TESTING INSTRUCTIONS

1. Check out this branch (needs feat(docs): expand docs:screenshots generator with manifest and tutorial captures #39444 merged first, or start local Docker with example data loaded)
2. cd superset-frontend
3. PLAYWRIGHT_BASE_URL=http://localhost:8088 PLAYWRIGHT_ADMIN_PASSWORD=admin npm run docs:screenshots
4. Verify the five tutorial PNGs under docs/static/img/tutorial/ regenerate cleanly

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

Stacked on #39444 — once that merges, this PR's base will rebase onto master.

🤖 Generated with Claude Code

[bito-code-review]

Bito Automatic Review Skipped - Branch Excluded

Bito didn't auto-review because the source or target branch is excluded from automatic reviews.
No action is needed if you didn't intend for the agent to review it. Otherwise, to manually trigger a review, type /review in a comment and save.
You can change the branch exclusion settings here, or contact your Bito workspace admin at evan@preset.io.

[netlify]

✅ Deploy Preview for superset-docs-preview ready!

Name	Link
🔨 Latest commit	d1b0736
🔍 Latest deploy log	https://app.netlify.com/projects/superset-docs-preview/deploys/69e4113b79d820000813079d
😎 Deploy Preview	https://deploy-preview-39466--superset-docs-preview.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.49%. Comparing base (406358c) to head (d1b0736).

Additional details and impacted files

@@                  Coverage Diff                   @@
##           feat/docs-screenshots   #39466   +/-   ##
======================================================
  Coverage                  64.49%   64.49%           
======================================================
  Files                       2557     2557           
  Lines                     133097   133097           
  Branches                   30910    30910           
======================================================
  Hits                       85846    85846           
  Misses                     45761    45761           
  Partials                    1490     1490           

Flag	Coverage Δ
javascript	66.33% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.