Search modal renders beneath the open AI dock (shared --z-overlay) #1293

Bug

With the AI dock open, opening the search modal (Cmd+K) paints the dock's Sources chips over the search palette. Screenshot: the "Sources" chip list bleeds across the search header and results.

Cause

SearchModal content and AiDock root both sit at z-[var(--z-overlay)] (1000), so nothing guarantees the modal paints above the dock.

• src/components/SearchModal.tsx:401 — search-modal-content fixed z-[var(--z-overlay)] ...
• src/components/AiDock.tsx dock root — fixed top-[var(--navbar-height)] right-0 bottom-0 z-[var(--z-overlay)] ...
• Tokens in src/styles/app.css: --z-scrim: 999, --z-overlay: 1000, --z-above-overlay: 1200

The search panel is bg-black/95, so the chips are genuinely painting above it, not bleeding through.

Fix

Smallest change: raise the search modal content to z-[var(--z-above-overlay)] and its overlay one step below, so the palette always sits over the dock. Alternative: close the dock when the search modal opens.

Reproduces on main; not introduced by ai-dock-agent-studio.