Fix drawer close and logo keyboard regressions

[hamzamerzic]

Summary

• consume the Shift+Enter logo mode activation so it does not also toggle navigation
• keep the mobile drawer scrim blocking until the closing panel is actually offscreen
• make workspace drag release flush the final coalesced move before committing
• tighten navigation/workspace E2E assertions for persistent desktop sidebar and real pane-center drops

Validation

• node --test frontend/src/components/Shell/tests/workspaceUi.test.js frontend/src/components/Shell/tests/mobileDrawerClose.test.js
• scripts/playwright-local.sh --allow-local-e2e tests/workspace-panes.spec.mjs tests/navigation.spec.mjs --project=tests --grep "logo gesture flips|single-mode drag|Closing scrim|breakpoint cleanup"