Convert portal shell from block-centered (max-width 1600px) layout to full-viewport
fluid flexbox with collapsible sidebar: desktop push-mode (240px → 0), mobile overlay
drawer with backdrop. Rename .content → .shell-content to avoid CSS collision with
page-level classes. Override page-level max-width constraints when embedded in shell.
Also replace native <select multiple> in query-tool with shared MultiSelect component
for equipment and workcenter group filters, matching resource-status/history UX.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
