Feature: refresh the current tab's data #33

Problem

Most queries are cached aggressively (refetchOnMount / refetchOnReconnect / refetchOnWindowFocus all disabled), which keeps the app fast and API-quota friendly — but it also means most tabs have no way to show fresh data. Inbox, Activity, and Action-run pages have their own refresh affordances, but Issue / PR / repository tabs only refetch after you perform a mutation. If someone comments on an issue you have open in a background tab, that tab stays stale until you interact with it or restart the app.

Proposal

A "refresh current tab" action that invalidates the currently active queries and refetches them in place (e.g. queryClient.invalidateQueries({ refetchType: 'active' })).

Notably, remounting the page component would not work as a refresh here: with refetchOnMount: false the remounted page just reads the stale cache back. In-place refetch is the correct lever, and it also preserves scroll position and any draft state (half-written comments), which a browser-style full reload would destroy.

Suggested entry points:

• A workspace.refresh keyboard shortcut (Primary+R), following the existing shortcut registry pattern
• Optionally a "Refresh" item in the tab context menu (building on feat(workspace): add tab context menu with batch close actions #26 / refactor(workspace): polish tab context menu #29)

Open questions

1. Scope: invalidating active queries refreshes everything currently mounted (sidebar lists included), not just the tab view. Is that acceptable, or would you prefer targeting queries per tab type?
2. Shortcut: Primary+R vs F5 — any conflict concerns with Electron defaults you'd want to avoid?

Happy to implement once the shape is agreed — I'd start after #29 lands, since the context-menu entry point touches the same files.