Rename Kill to Close, add New Terminal palette entry, clean up exited terminals

- Palette's per-child "Kill <name>" action is now labelled "Close <name>"
  (action kind unchanged; still SIGTERM). Matches the existing "Close
  agent: …" context entry and reads less violent for a graceful term.
- New "New Terminal" palette entry spawns a bare interactive $SHELL pane
  via LaunchTerminal (kind=terminal). Replaces the default "shell"
  process preset that was seeded on first run.
- Exited KindTerminal entries are now dropped from the session in
  reapChild — terminals have no restart path, so leaving them behind as
  greyed rows in the Processes sidebar was just clutter. processList
  also filters defensively.

internal/app/app.go

@@ -1622,6 +1622,13 @@ func (st *uiState) closePalette(action paletteAction) {
 			st.flashError(fmt.Sprintf("spawn %s: %v", action.preset.Name, err))
 		}
 
+	case "spawn-terminal":
+		l := st.layoutSnapshot()
+		st.launcher.SetSize(l.childCols(), l.childRows())
+		if _, err := st.launcher.LaunchTerminal(nil, "terminal", "", "", nil); err != nil {
+			st.flashError(fmt.Sprintf("spawn terminal: %v", err))
+		}
+
 	case "spawn-process-submit":
 		if action.command == "" {
 			restoreView()

internal/app/palette.go

@@ -11,12 +11,13 @@ import (
 // paletteAction is what the palette returns when the user picks an item.
 type paletteAction struct {
 	// kind: "spawn-agent" | "spawn-process" | "spawn-process-form" |
-	//       "spawn-process-submit" | "switch" | "kill" | "quit" |
-	//       "cancel" | "pad-delete" | "pad-rename" | "pad-rename-form" |
-	//       "pad-rename-submit" | "pad-edit" | "agent-rename" |
-	//       "agent-rename-form" | "agent-rename-submit" | "agent-close" |
-	//       "proc-rename" | "proc-rename-form" | "proc-rename-submit" |
-	//       "proc-delete" | "proc-stop" | "proc-restart"
+	//       "spawn-process-submit" | "spawn-terminal" | "switch" |
+	//       "kill" | "quit" | "cancel" | "pad-delete" | "pad-rename" |
+	//       "pad-rename-form" | "pad-rename-submit" | "pad-edit" |
+	//       "agent-rename" | "agent-rename-form" | "agent-rename-submit" |
+	//       "agent-close" | "proc-rename" | "proc-rename-form" |
+	//       "proc-rename-submit" | "proc-delete" | "proc-stop" |
+	//       "proc-restart"
 	kind string
 
 	// For spawn-agent / spawn-process, the preset to launch.
@@ -276,6 +277,16 @@ func (p *paletteState) allItems() []paletteItem {
 		})
 	}
 
+	// "New Terminal" — bare interactive $SHELL pane. Distinct from
+	// "Run process: …" presets in that it spawns a KindTerminal (which
+	// disappears from the sidebar on exit rather than sticking around
+	// for restart). One quick keystroke; no form.
+	out = append(out, paletteItem{
+		label:  "New Terminal",
+		hint:   "bare interactive $SHELL · removed on exit",
+		action: paletteAction{kind: "spawn-terminal"},
+	})
+
 	// Freeform "Spawn process…" entry. Opens a sub-form for typing an
 	// arbitrary command line and ticking "relaunch on exit". The action
 	// kind is intercepted by acceptOrEnterForm so accept switches the
@@ -288,14 +299,14 @@ func (p *paletteState) allItems() []paletteItem {
 		action: paletteAction{kind: "spawn-process-form"},
 	})
 
-	// Kill entries last among the action rows, before Quit. Mirror the
+	// Close entries last among the action rows, before Quit. Mirror the
 	// "(current)" marker from switch entries so the focused tab is
-	// obvious when scanning the kill list.
+	// obvious when scanning the close list.
 	for _, c := range p.children {
 		if c.Status() != StatusRunning {
 			continue
 		}
-		label := "Kill " + c.DisplayName()
+		label := "Close " + c.DisplayName()
 		if c.ID == p.focused {
 			label = "• " + label + " (current)"
 		}

internal/app/session.go

@@ -433,6 +433,23 @@ func (s *Session) reapChild(c *Child, runID uint64) {
 	if !c.restarting.Load() {
 		c.cleanupOwnedPaths()
 	}
+	// Terminals are ephemeral: unlike command entries (kept around for
+	// restart_process) and agents (which the user clears via close_process
+	// once they're done with the corpse), an exited terminal has nothing
+	// useful left to do. Drop it from the session so it disappears from
+	// the Processes sidebar / switch list immediately.
+	if c.Kind == KindTerminal && !c.restarting.Load() {
+		c.teardownPTY()
+		s.mu.Lock()
+		delete(s.children, c.ID)
+		for i, oid := range s.order {
+			if oid == c.ID {
+				s.order = append(s.order[:i], s.order[i+1:]...)
+				break
+			}
+		}
+		s.mu.Unlock()
+	}
 }
 
 // killDescendantsOf terminates every still-live direct child of

internal/app/tree.go

@@ -96,17 +96,24 @@ func firstRunningAgentID(children []*Child) string {
 }
 
 // processList returns every top-level command/terminal entry in spawn
-// order, regardless of running state. The Processes sidebar section
-// keeps showing exited entries so the user can see what just died (and
-// because Session retains KindCommand entries for restart).
+// order. Exited KindCommand entries remain visible so the user can see
+// what just died and reach restart_process; exited KindTerminal entries
+// are filtered out because terminals are ephemeral and have no restart
+// path (Session also drops them in reapChild — this filter is defensive
+// for any window between exit and deletion).
 func processList(children []*Child) []*Child {
 	out := make([]*Child, 0, len(children))
 	for _, c := range children {
 		if c.ParentID != "" {
 			continue
 		}
-		if c.Kind == KindCommand || c.Kind == KindTerminal {
+		switch c.Kind {
+		case KindCommand:
 			out = append(out, c)
+		case KindTerminal:
+			if c.Status() == StatusRunning {
+				out = append(out, c)
+			}
 		}
 	}
 	return out