fix(rpc-client): 15min timeout on package.install for multi-GB stacks

IndeedHub, Bitcoin, and Penpot installs routinely exceed the default
RPC timeout on first pull. Bump package.install specifically to
900s so the frontend doesn't drop the request while the backend is
still downloading images.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/api/rpc-client.ts

@@ -510,6 +510,7 @@ class RPCClient {
     return this.call({
       method: 'package.install',
       params: { id, 'marketplace-url': marketplaceUrl, version },
+      timeout: 900000, // 15 min — multi-GB stacks (IndeedHub, Bitcoin, Penpot) take time
     })
   }