fix: handle Enter key pressed during model loading

When users type and press Enter while a model is loading (terminal in
cooked mode), the newline character is buffered as \n (LF). In raw mode,
Enter sends \r (CR) while Ctrl+J sends \n. This caused buffered Enter
keystrokes to be misinterpreted as Ctrl+J, incorrectly triggering
multiline input mode instead of submitting the message.

This change detects when we're processing buffered input from cooked
mode by checking if there's additional data in the read buffer after
each character read. When draining such input, \n is treated as submit
rather than multiline.

Also fixes the """ multiline prompt to consistently show "..." instead
of ">>>" after each line.

cmd/interactive.go

@@ -159,6 +159,7 @@ func generateInteractive(cmd *cobra.Command, opts runOptions) error {
 			sb.WriteString(before)
 			if !ok {
 				fmt.Fprintln(&sb)
+				scanner.Prompt.UseAlt = true
 				continue
 			}
 

readline/readline.go

@@ -95,7 +95,21 @@ func (i *Instance) Readline() (string, error) {
 
 	var currentLineBuf []rune
 
+	// draining tracks if we're processing buffered input from cooked mode.
+	// In cooked mode Enter sends \n, but in raw mode Ctrl+J sends \n.
+	// We treat \n from cooked mode as submit, not multiline.
+	// We check Buffered() after the first read since the bufio buffer is
+	// empty until then. This is compatible with """ multiline mode in
+	// interactive.go since each Readline() call is independent.
+	var draining, stopDraining bool
+
 	for {
+		// Apply deferred state change from previous iteration
+		if stopDraining {
+			draining = false
+			stopDraining = false
+		}
+
 		// don't show placeholder when pasting unless we're in multiline mode
 		showPlaceholder := !i.Pasting || i.Prompt.UseAlt
 		if buf.IsEmpty() && showPlaceholder {
@@ -105,6 +119,15 @@ func (i *Instance) Readline() (string, error) {
 
 		r, err := i.Terminal.Read()
 
+		// After reading, check if there's more buffered data. If so, we're
+		// processing cooked-mode input. Once buffer empties, the current
+		// char is the last buffered one (still drain it), then stop next iteration.
+		if i.Terminal.reader.Buffered() > 0 {
+			draining = true
+		} else if draining {
+			stopDraining = true
+		}
+
 		if buf.IsEmpty() {
 			fmt.Print(ClearToEOL)
 		}
@@ -232,15 +255,20 @@ func (i *Instance) Readline() (string, error) {
 			fd := os.Stdin.Fd()
 			return handleCharCtrlZ(fd, i.Terminal.termios)
 		case CharCtrlJ:
-			i.pastedLines = append(i.pastedLines, buf.String())
-			buf.Buf.Clear()
-			buf.Pos = 0
-			buf.DisplayPos = 0
-			buf.LineHasSpace.Clear()
-			fmt.Println()
-			fmt.Print(i.Prompt.AltPrompt)
-			i.Prompt.UseAlt = true
-			continue
+			// If not draining cooked-mode input, treat as multiline
+			if !draining {
+				i.pastedLines = append(i.pastedLines, buf.String())
+				buf.Buf.Clear()
+				buf.Pos = 0
+				buf.DisplayPos = 0
+				buf.LineHasSpace.Clear()
+				fmt.Println()
+				fmt.Print(i.Prompt.AltPrompt)
+				i.Prompt.UseAlt = true
+				continue
+			}
+			// Draining cooked-mode input: treat \n as submit
+			fallthrough
 		case CharEnter:
 			output := buf.String()
 			if len(i.pastedLines) > 0 {