feat(tui): add cards view, mode switching, promote picker, and card detail

Stream/cards toggle with 1/2 keys. Cards view with intent filtering
(tab cycles grab/read/fill/all), sort cycling (s key), pinned-first
ordering, and affordance badges. Promote picker (p key) with card type
selection and auto-detection from body content. Detail view renders
card_data per type: checklist steps, template slots, decision fields,
link URLs.

Extracts generateCardData to internal/carddata for reuse across cmd
and tui packages.

internal/tui/statusbar.go

@@ -23,7 +23,12 @@ func renderStatusBar(m model, width int) string {
 }
 
 func countText(m model) string {
-	total := len(m.list.entities)
+	var total int
+	if m.mode == modeCards {
+		total = len(m.cards.filtered)
+	} else {
+		total = len(m.list.entities)
+	}
 	if m.filterTag != "" {
 		return fmt.Sprintf("%d entities #%s", total, m.filterTag)
 	}
@@ -40,7 +45,12 @@ func contextHints(m model) string {
 		return "j/k:nav enter:select esc:cancel"
 	case stateConfirm:
 		return "y:confirm n:cancel"
+	case statePromote:
+		return "j/k:nav enter:select esc:cancel"
 	default:
-		return "a:add d:del x:todo #:filter ?:help q:quit"
+		if m.mode == modeCards {
+			return "1:stream 2:cards s:sort tab:intent a:add ?:help q:quit"
+		}
+		return "1:stream 2:cards a:add d:del x:todo #:filter ?:help q:quit"
 	}
 }