A per-model runnability report for the current device — the feasibility check you want before a multi-GB download: a pass/fail RAM-headroom bar (model RAM vs device RAM), available storage, threading (cross-origin-isolation) status, estimated speed, and a warnings list, with a canRun boolean gating a success/error header. Ships an independently-usable RAMUsageBar. Extends the spirit of CapabilityGate; data source useCapabilities.