In a remote-development window every settings read went to the server, so the keymap (preset, overrides, custom keymaps) and other UI preferences came from the server's global settings — defaults on a fresh host — and customised shortcuts were lost. Client-scoped settings are now declared in one place (src/platform/clientSettings.ts: keymap, appearance, notifications, editor typography and display, terminal typography and interaction, and UI-only general/console/debugger/run/VCS preferences). In remote windows they are overlaid from the local global settings on every settings response (settings_get, settings_set, project snapshots, connect), and writes to them go to the local backend only. Project and tooling settings still come from the server.
Not verified against a real SSH host (none available here); covered by routing and overlay tests.
Fixes#239
