Panels: add global search

[Verma-Punit]

What problem does this address?

Users have to click into each resource (like “Users,” “Invoices,” “Members”) and use its own search. This takes too much time when there are many resources.

Proposed solution

Integrate global search feature into the panels layout so that a single search input at the top of the sidebar (or header) will query across all registered resources.

Additional context

No response