fix(dashboard): scope delayed mutations to owner

[HandSonic]

Related issue

N/A - no matching issue or PR was found for the delayed dashboard mutation race.

Summary

Dashboard mutations committed against whatever dashboard happened to be active when their promises resolved. A delayed save for dashboard A could replace newly selected dashboard B, while a delayed chart deletion could remove the chart from B and persist the wrong dashboard. This change keeps saves scoped to their dashboard ID, captures chart-deletion ownership before awaiting the API, updates the owning list entry, and leaves a different active dashboard/settings panel untouched.

Affected surfaces

• Frontend / Web
• Backend / API / Storage
• Database plugin / Driver
• JCEF / Desktop packaging
• CI / Build / Release
• Documentation only

Verification

• Red tests reproduced delayed A-save and A-delete completion after selecting B.
• Dashboard mutation tests cover stale save ownership, same-dashboard merge, deletion snapshot/fallback, filtered layout, missing IDs, and active-settings ownership.
• Full Community prebuild suite: passed.
• Targeted ESLint and diff checks: passed.
• Playwright: A title save was delayed 6 seconds, B was selected immediately, B remained active before/after completion, and A's list title still updated.
• Pairwise merge-tree checks with fix(client): ignore stale dashboard details #2836 and fix(dashboard): settle failed refresh requests #2688: passed.
• Fork Frontend, Backend, and JavaScript CodeQL checks: passed; unchanged Java CodeQL is still running.

Risk and compatibility

No API or persisted-data format changes. Updates for the active dashboard retain the existing merge behavior. When another dashboard is active, only the owning dashboard-list entry changes. Chart deletion still persists the original dashboard's filtered chart IDs/schema.

Reviewer map

• Start with dashboardMutation.ts, then createCommonAction.updateDashboard and deleteChart.
• Failure condition: an A mutation changes current dashboard B, closes B settings, or persists B after deleting from A.
• Rollback: revert b0d6cd3451d1dd3fe5ac928150850d0ae0a95258; no migration is required.

Contributor declaration

• I linked the issue that defines this change.
• I tested the affected behavior and reported the actual results above.
• I did not include credentials, private data, or generated build output.
• I disclosed substantial AI assistance below.

AI assistance: OpenAI Codex assisted with diagnosis, implementation, tests, Playwright verification, and adversarial review.