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/keys.go

@@ -22,6 +22,10 @@ type keyMap struct {
 	Demote  key.Binding
 	Copy    key.Binding
 	Edit    key.Binding
+	Stream  key.Binding
+	Cards   key.Binding
+	Sort    key.Binding
+	Intent  key.Binding
 }
 
 var keys = keyMap{
@@ -44,4 +48,8 @@ var keys = keyMap{
 	Demote:  key.NewBinding(key.WithKeys("D"), key.WithHelp("D", "demote")),
 	Copy:    key.NewBinding(key.WithKeys("c"), key.WithHelp("c", "copy")),
 	Edit:    key.NewBinding(key.WithKeys("e"), key.WithHelp("e", "edit")),
+	Stream:  key.NewBinding(key.WithKeys("1"), key.WithHelp("1", "stream")),
+	Cards:   key.NewBinding(key.WithKeys("2"), key.WithHelp("2", "cards")),
+	Sort:    key.NewBinding(key.WithKeys("s"), key.WithHelp("s", "sort")),
+	Intent:  key.NewBinding(key.WithKeys("tab"), key.WithHelp("tab", "intent")),
 }