feat: add character limit display and keyboard shortcut hint

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

app.py

@@ -86,7 +86,7 @@ def translate(
 
 
 def _update_char_count(text: str) -> str:
-    return f"{len(text)} characters"
+    return f"{len(text)} / 2,000"
 
 
 def _build_demo() -> gr.Blocks:
@@ -105,7 +105,9 @@ def _build_demo() -> gr.Blocks:
                     lines=6,
                     show_label=False,
                 )
-                char_count = gr.Markdown("0 characters")
+                with gr.Row():
+                    char_count = gr.Markdown("0 / 2,000")
+                    gr.Markdown("Ctrl+Enter to submit")
             with gr.Column():
                 target_language = gr.Dropdown(
                     choices=language_names,
@@ -141,7 +143,7 @@ def _build_demo() -> gr.Blocks:
             outputs=char_count,
         )
         clear_btn.click(
-            fn=lambda: ("", "", "0 characters"),
+            fn=lambda: ("", "", "0 / 2,000"),
             outputs=[input_text, output_text, char_count],
         )
 

tests/test_app.py

@@ -201,6 +201,20 @@ def test_input_textbox_has_no_placeholder(demo):
     assert interactive[0].placeholder is None, f"Expected no placeholder, got {interactive[0].placeholder!r}"
 
 
+def test_char_count_shows_limit(demo):
+    """Character count should show '0 / 2,000' format."""
+    markdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Markdown"]
+    limit_mds = [m for m in markdowns if "2,000" in m.value]
+    assert len(limit_mds) == 1, f"Expected one markdown with '2,000', found {len(limit_mds)}"
+
+
+def test_shortcut_hint_exists(demo):
+    """Keyboard shortcut hint should be visible."""
+    markdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Markdown"]
+    hints = [m for m in markdowns if "Ctrl+Enter" in m.value]
+    assert len(hints) == 1, f"Expected one shortcut hint, found {len(hints)}"
+
+
 # --- Slow tests (require CUDA + model download) ---
 
 gpu_available = torch.cuda.is_available()