With the backend flipped to async-spawn, install/uninstall/update return
immediately with a { status, package_id } envelope. Client timeouts of
45m/11m were a leftover from synchronous handlers and masked real RPC
failures.
Drop all install/uninstall/update RPC timeouts to 15s. Progress and
terminal state still arrive through the live state stream — the RPC
only needs to confirm the spawn was accepted.
Return-type annotations updated in rpc-client.ts and stores/server.ts.
Five direct rpcClient.call sites across Marketplace.vue, Discover.vue,
and MarketplaceAppDetails.vue updated with the shorter timeout.