fix: sync fullscreen routes

[oiahoon]

Summary

• append /view when fullscreen opens from the root or edited route
• add valid application routes for /view and /edited/view
• cover entering and exiting fullscreen from both routes with Playwright

Root cause

Fullscreen URL synchronization explicitly skipped / and /edited, and the router did not mount the application at their corresponding /view paths.

Validation

• npx vitest --project unit (37 tests)
• npx playwright test --project=chromium (84 tests)
• npm run lint
• npx tsc
• npm run build
• git diff --check

Closes #1508