feat(tui): always-visible capture bar with focus cycling

Replace drawer-based input with permanent capture bar at bottom.
Focus defaults to capture on startup — open nib, start typing.

- Remove stateInput; route via focusCapture/focusList/focusDetail
- Tab cycles: capture → list → detail (split) → capture
- Esc cascades: clear search → clear filter → focus capture
- Capture bar shows blinking cursor when focused, dims when not
- Intent cycling moved from tab to i (tab now cycles focus)
- Parse preview shown inline in status bar while typing
- Content area constant height (no layout thrash from drawer)

internal/tui/keys.go

@@ -7,7 +7,7 @@ type keyMap struct {
 	Down       key.Binding
 	Enter      key.Binding
 	Back       key.Binding
-	Add        key.Binding
+	Capture    key.Binding
 	Delete     key.Binding
 	Quit       key.Binding
 	Help       key.Binding
@@ -31,6 +31,7 @@ type keyMap struct {
 	Fill       key.Binding
 	FocusLeft  key.Binding
 	FocusRight key.Binding
+	Tab        key.Binding
 }
 
 var keys = keyMap{
@@ -38,7 +39,7 @@ var keys = keyMap{
 	Down:       key.NewBinding(key.WithKeys("down", "j"), key.WithHelp("↓/j", "down")),
 	Enter:      key.NewBinding(key.WithKeys("enter"), key.WithHelp("enter", "view")),
 	Back:       key.NewBinding(key.WithKeys("esc"), key.WithHelp("esc", "back")),
-	Add:        key.NewBinding(key.WithKeys("a"), key.WithHelp("a", "add")),
+	Capture:    key.NewBinding(key.WithKeys("a"), key.WithHelp("a", "capture")),
 	Delete:     key.NewBinding(key.WithKeys("d"), key.WithHelp("d", "delete")),
 	Quit:       key.NewBinding(key.WithKeys("q", "ctrl+c"), key.WithHelp("q", "quit")),
 	Help:       key.NewBinding(key.WithKeys("?"), key.WithHelp("?", "help")),
@@ -56,10 +57,11 @@ var keys = keyMap{
 	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")),
+	Intent:     key.NewBinding(key.WithKeys("i"), key.WithHelp("i", "intent")),
 	Absorb:     key.NewBinding(key.WithKeys("m"), key.WithHelp("m", "absorb")),
 	Run:        key.NewBinding(key.WithKeys("r"), key.WithHelp("r", "run checklist")),
 	Fill:       key.NewBinding(key.WithKeys("f"), key.WithHelp("f", "fill template")),
 	FocusLeft:  key.NewBinding(key.WithKeys("h"), key.WithHelp("h", "focus list")),
 	FocusRight: key.NewBinding(key.WithKeys("l"), key.WithHelp("l", "focus detail")),
+	Tab:        key.NewBinding(key.WithKeys("tab"), key.WithHelp("tab", "focus cycle")),
 }