Preserve search results after directory changes

[shriram-svg]

Closes: #18

What are the changes and their implications?

This keeps per-view search state for the active query/folder. When a directory update arrives after a file operation, droppy now re-runs the active search instead of replacing the results with the full directory listing. Search results also restore the search input state, and opening a file preserves the active search so browser Back can return to the filtered result list.

The search response now echoes the query so the client can ignore stale results when a newer query is active.

Verification

• git diff --check
• yarn lint (passes; reports existing warnings)
• yarn biome check packages/client/lib/client.js packages/server/src/commands/search.ts (passes; reports existing unused normalize warning in client.js)
• yarn workspace @droppyjs/server build
• yarn test

yarn build was attempted, but the existing resource build fails looking for workspace-local client dependency paths such as node_modules/handlebars/dist/handlebars.runtime.min.js under the client package.

Checklist

• Changes covered by tests (tests added if needed)
• PR submitted to droppyjs.com for any user facing changes