929ba007bb
Fold the skill hub (search/preview/scan/install, from #57441) into Capabilities as a fourth "Browse Hub" tab, rebuilt on our stack: - sources + debounced term search + preview are useQuery-driven (RQ dedupes/ caches per term, cancels stale terms — no hand-rolled sequence guard). - Each result is a self-contained HubSkillRow that installs/uninstalls ITSELF, reading its own status from a nanostore (store/hub-actions). Concurrent installs never desync; an optimistic installed-override flips a row the instant its own action resolves instead of racing the sources refetch. - Action log bubbles through a $hubActiveLog atom into the shared LogTail in a collapsed-by-default, persistent bottom DetailPane (ANSI stripped).