feat: re-echo condensed user prompt in chat log

Shows user input as a compact one-liner ("You: prompt text") instead of
a full panel. Multi-line input is collapsed to the first line with a
"(+N lines)" suffix, and long lines are truncated at 120 chars.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/utils/display.py

@@ -44,9 +44,22 @@ if TYPE_CHECKING:
 # ---------------------------------------------------------------------------
 
 
-def render_user_message(content: str) -> Panel:
-    """Render a user message as a styled panel."""
-    return Panel(content, title="You", border_style="cyan", expand=False)
+def render_user_message(content: str) -> Text:
+    """Render a condensed user prompt as a single styled line.
+
+    Multi-line input is collapsed to the first line with a line count suffix.
+    Long single lines are truncated.
+    """
+    lines = content.splitlines()
+    first = lines[0] if lines else content
+    max_len = 120
+    if len(first) > max_len:
+        first = first[:max_len] + "…"
+    suffix = f" (+{len(lines) - 1} lines)" if len(lines) > 1 else ""
+    text = Text()
+    text.append("You: ", style="bold cyan")
+    text.append(first + suffix, style="cyan")
+    return text
 
 
 def render_assistant_message(content: str) -> Panel:
@@ -223,8 +236,8 @@ def print_success(message: str) -> None:
 
 
 def print_user_message(content: str) -> None:
-    """Print a user message in a styled panel."""
-    console.print(Panel(content, title="You", border_style="cyan", expand=False))
+    """Print a condensed user prompt line."""
+    console.print(render_user_message(content))
 
 
 def print_assistant_message(content: str) -> None: