WorkspaceShell inspector rail overlaps content on mobile

[willgriffin]

Summary

When WorkspaceShell renders an inspectorRail without an open inspector at the mobile breakpoint (max-width: 960px), the rail is fixed to the right edge but .smrt-workspace-content and .smrt-workspace-topbar are reset to --smrt-ws-page-pad padding. Content can slide underneath the rail, so right-aligned controls become partially covered.

Reproduction

1. Render WorkspaceShell with an inspectorRail snippet and showInspector={false}.
2. Use a viewport at or below 960px wide.
3. Place a right-aligned action in the page header/topbar.

Expected

The content/topbar reserve the rail width while the rail is visible and the inspector panel is closed.

Actual

The mobile media rule resets right padding to the normal page pad, leaving content under the fixed rail.

Notes

I hit this while moving local admin add/edit tools into the WorkspaceShell inspector rail. A local override confirmed that reserving calc(var(--smrt-ws-rail-width) + 1rem) fixes the overlap.

[willgriffin]

This was generated by AI during triage.

Verified still present in current main: the mobile media rule in WorkspaceShell.svelte resets right padding for the rail-only state, matching the reported overlap. Added to batch fixup epic #1294.