Fix analytics connection isolation and layout

[thebuilder]

Summary

• clear report state when switching analytics connections so demo results cannot appear for a real project
• lay out Flags beside Events in the overview while retaining the page-specific document layout
• add regressions for failed connection switches and both grid variants

Root cause

Connection changes reused previous asynchronous report data while the next project loaded. The grid also applied the same centered Flags layout in every context.

Verification

• CI=true corepack pnpm test src/analytics/analytics-dashboard.controller.test.ts src/analytics/analytics-components.test.ts
• CI=true corepack pnpm build
• git diff --check