Function describe_inbound_class 

pub fn describe_inbound_class(c: &InboundClass) -> String

UX-P4-7: SCREEN-ONLY human summary of an InboundClass decision payload (income / received gift / self-transfer). Replaces the raw {:?} Debug dump (SelfTransferMine { basis: Some(19000.00), acquired_at: Some(2026-01-01) }) that the CLI bulk-void preview + TUI void list truncated mid-field. Like pseudo_tag [R0-I4], this is for the terminal ONLY — the CSV/form writers MUST NOT call it (they emit stable machine tags via *_tag), so no human phrasing can leak into an export file.