fix(tui): warn when /copy-session-id runs before a session exists

internal/tui/clipboard.go

@@ -242,7 +242,7 @@ func validSessionID(id string) bool {
 // for a later `bodek --session <id>`. The ✓ Copied flash is the only ack.
 func (m *Model) copySessionID() tea.Cmd {
 	if !validSessionID(m.sessionID) {
-		return m.transientNoteCmd("no active session yet")
+		return m.transientNoteCmd("no session yet — the id exists once a session is created; send a prompt first")
 	}
 	return m.copyText(m.sessionID)
 }

internal/tui/copy_session_id_test.go

@@ -1,6 +1,7 @@
 package tui
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/BackendStack21/bodek/internal/workspace"
@@ -47,6 +48,13 @@ func TestCopySessionIDWithoutSession(t *testing.T) {
 	if m.copyFlashing() {
 		t.Error("nothing was copied — the flash must stay off")
 	}
+	// The note must warn and teach: the id only exists once a session is
+	// created (first prompt), so the operator knows to send a prompt first.
+	if n := len(m.notices); n == 0 {
+		t.Fatal("no-session copy must record a visible note")
+	} else if got := m.notices[n-1]; !strings.Contains(got, "no session") || !strings.Contains(got, "prompt") {
+		t.Errorf("note = %q, want a warning naming the session and a prompt hint", got)
+	}
 }
 
 // A hostile id must never reach the clipboard — the payload is a