fix(desktop): show agent-created schedules on the Schedules page (#13613)

* fix(desktop): show agent-created schedules on the Schedules page

Schedule hub commands are scoped to the workspace registered by the
connection, but the desktop app's hub client registers the app launch
directory while agent-created schedules live under each chat's own
workspace folder - so they never appeared on the Schedules page.

Grant token-authenticated hub connections (which can already bind any
workspace at registration) explicit cross-workspace schedule access via
an allWorkspaces payload flag, and have the desktop sidecar request it
for routine schedule commands. Workspace-bound clients (local browser
origins) and default CLI behavior stay scoped.

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

* refactor(core): strip allWorkspaces flag from schedule inputs and pin it in the sidecar payload

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

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Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>