feat(tui): ctrl+v pastes a clipboard image into the first prompt

cmd/uishot/testdata/new-session-multiline.txt

@@ -48,7 +48,7 @@
            │                                                                            │           
            │                                                                            │           
            │  optional — the agent's first task; enter for a newline, tab away to       │           
-           │  submit                                                                    │           
+           │  submit, ctrl+v pastes an image                                            │           
            │  tab/↑↓ fields  ←→ choose  enter  esc cancel                               │           
            │                                                                            │           
            ╰────────────────────────────────────────────────────────────────────────────╯           

cmd/uishot/testdata/new-session-wide-line.txt

@@ -48,7 +48,7 @@
            │                                                                            │           
            │                                                                            │           
            │  optional — the agent's first task; enter for a newline, tab away to       │           
-           │  submit                                                                    │           
+           │  submit, ctrl+v pastes an image                                            │           
            │  tab/↑↓ fields  ←→ choose  enter  esc cancel                               │           
            │                                                                            │           
            ╰────────────────────────────────────────────────────────────────────────────╯           

internal/tui/clipimage.go

@@ -0,0 +1,65 @@
+package tui
+
+import (
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+// clipboardImage saves an image on the system clipboard to a temp PNG and
+// returns its path, or an error when there is no image (or no way to read
+// one). Ctrl+V in the prompt field calls it before falling back to the
+// textarea's own text paste — the same trick Claude Code uses, since a
+// terminal paste (Cmd+V) only ever carries text.
+//
+// It reads *this* process's clipboard, so it's front-end work (see the
+// client/core split in AGENTS.md), and over SSH it sees the host's
+// clipboard, not the viewer's — which in practice means no image, and a
+// plain text paste.
+//
+// A var so tests can stub it.
+//
+// ponytail: macOS only (osascript); add wl-paste/xclip when someone runs
+// the TUI on a Linux desktop.
+var clipboardImage = func() (string, error) {
+	if runtime.GOOS != "darwin" {
+		return "", os.ErrNotExist
+	}
+	f, err := os.CreateTemp("", "moomux-paste-*.png")
+	if err != nil {
+		return "", err
+	}
+	path := f.Name()
+	f.Close()
+	script := `set f to open for access (POSIX file "` + path + `") with write permission
+try
+	write (the clipboard as «class PNGf») to f
+	close access f
+on error e
+	close access f
+	error e
+end try`
+	if err := exec.Command("osascript", "-e", script).Run(); err != nil {
+		os.Remove(path)
+		return "", err
+	}
+	return path, nil
+}
+
+// pasteClipboardImage inserts a clipboard image's path at the prompt's
+// cursor, reporting whether there was one. Agents read an image path in a
+// prompt as the image.
+func (m *Model) pasteClipboardImage() bool {
+	path, err := clipboardImage()
+	if err != nil {
+		return false
+	}
+	// Space-padded so the path never fuses with neighbouring text.
+	sep := " "
+	if v := m.promptInput.Value(); v == "" || strings.HasSuffix(v, " ") || strings.HasSuffix(v, "\n") {
+		sep = ""
+	}
+	m.promptInput.InsertString(sep + path + " ")
+	return true
+}

internal/tui/form.go

@@ -191,7 +191,7 @@ var newFormFieldHints = []string{
 	1:  "list + folder name — blank: from branch, prompt, or random",
 	2:  "resume an existing branch; blank = new branch off base",
 	3:  "only used for a new branch — blank uses the project's base branch",
-	4:  "optional — the agent's first task; enter for a newline, tab away to submit",
+	4:  "optional — the agent's first task; enter for a newline, tab away to submit, ctrl+v pastes an image",
 	5:  "optional — shown as a clickable ticket icon next to the session",
 	6:  "optional — shown as a clickable PR icon next to the session",
 	7:  "which agent CLI runs in the session's pane — ←→ to choose",

internal/tui/update.go

@@ -1419,6 +1419,9 @@ func (m *Model) updateNewForm(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	case newFormBaseBranchFocus:
 		m.baseBranchInput, cmd = m.baseBranchInput.Update(msg)
 	case newFormPromptFocus:
+		if msg.String() == "ctrl+v" && m.pasteClipboardImage() {
+			break
+		}
 		m.promptInput, cmd = m.promptInput.Update(msg)
 	case newFormTicketFocus:
 		m.ticketInput, cmd = m.ticketInput.Update(msg)

internal/tui/update_test.go

@@ -1856,3 +1856,30 @@ func TestUpdateFlashSurvivesWhileBrewRuns(t *testing.T) {
 		t.Fatalf("expected busy to clear once the update finishes")
 	}
 }
+
+// TestNewSessionPromptCtrlVPastesClipboardImagePath guards the image paste:
+// ctrl+v on the prompt with an image on the clipboard inserts the saved
+// file's path (agents read that as the image); with no image it must fall
+// through to the textarea's normal text paste rather than swallow the key.
+func TestNewSessionPromptCtrlVPastesClipboardImagePath(t *testing.T) {
+	orig := clipboardImage
+	t.Cleanup(func() { clipboardImage = orig })
+
+	be := &fakeBackend{}
+	m := newTestModel(be)
+	m.Update(keyRune("n"))
+	tabTo(t, m, newFormPromptFocus)
+	typeText(m, "look at")
+
+	clipboardImage = func() (string, error) { return "/tmp/moomux-paste-1.png", nil }
+	m.Update(tea.KeyMsg{Type: tea.KeyCtrlV})
+	if got := m.promptInput.Value(); got != "look at /tmp/moomux-paste-1.png " {
+		t.Fatalf("prompt = %q", got)
+	}
+
+	clipboardImage = func() (string, error) { return "", os.ErrNotExist }
+	_, cmd := m.Update(tea.KeyMsg{Type: tea.KeyCtrlV})
+	if cmd == nil {
+		t.Fatal("no image: ctrl+v should fall through to the textarea's text paste")
+	}
+}