* fix(sidebar): show chat-only workspaces as active before the first message
A workspace whose only tab is a native chat showed the grey Inactive dot
until a message was sent, because the dot counted only live terminals and
browser tabs. Count a chat that is not explicitly slept, the same rule the
sleeping-workspace check already uses, in the sidebar cards, the parent
picker and the Cmd+J switcher.
* test: bound chat status work on unrelated store writes
* test: correct chat status contract formatting
* test: use a fixed clock for chat status fixtures
* test: prune obsolete chat status clock allowance
* test: complete sidebar status store fixtures