feat(app): show generation progress and rename app heading

- Disable the run button and show a "Генерация…" status while a request is
  processing, then re-enable it. Repeated generations previously gave no
  visible feedback once the model was cached, so it was unclear whether a
  request was running.
- Append elapsed time to the final status so identical re-runs differ visibly.
- Rename the H1 heading and browser/tab title to
  "генератор аккордовых последовательностей".

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app.py

@@ -22,6 +22,7 @@ import tempfile
 from dataclasses import replace
 from functools import lru_cache
 from pathlib import Path
+from time import perf_counter
 from uuid import uuid4
 
 import gradio as gr
@@ -106,6 +107,7 @@ def generate(
     tempo: int,
 ):
     """Run one generation and return (status, bar grid, .chord path, .mid path)."""
+    t0 = perf_counter()
     try:
         model = _load_model(checkpoint)
     except Exception as exc:  # noqa: BLE001 — surface any load error to the UI
@@ -160,15 +162,37 @@ def generate(
     write_chord_file(period, chord_path)
     chord_file_to_midi(chord_path, midi_path, tempo=int(tempo))
 
+    elapsed = perf_counter() - t0
     status = (
         f"✅ Готово — {len(period.bars)} тактов · {target_key} · "
-        f"модель: {checkpoint} · seed: {seed_val if seed_val is not None else 'random'}"
+        f"модель: {checkpoint} · seed: {seed_val if seed_val is not None else 'random'} · "
+        f"{elapsed:.2f} с"
     )
     if truncated:
         status += f" · обрезано до {MAX_PERIOD_BARS} тактов (период ≤ 16)"
     return status, _format_bars(period), str(chord_path), str(midi_path)
 
 
+# ---------------------------------------------------------------------------
+# Button-state helpers — give immediate, persistent feedback while generating.
+# Gradio's built-in spinner barely flashes once the model is cached, so we also
+# disable the button and show a "generating" status until the work completes.
+# ---------------------------------------------------------------------------
+
+def _begin_generation():
+    """Show a busy state the instant the button is clicked (runs before generate)."""
+    return (
+        gr.update(value="⏳ Генерация…", interactive=False),  # run button
+        "⏳ Генерация…",                                       # status message
+        "",                                                    # clear the previous grid
+    )
+
+
+def _end_generation():
+    """Restore the run button after generation finishes (success or handled error)."""
+    return gr.update(value="Сгенерировать", interactive=True)
+
+
 # ---------------------------------------------------------------------------
 # Russian instructions (rendered inline)
 # ---------------------------------------------------------------------------
@@ -220,9 +244,9 @@ def build_ui() -> gr.Blocks:
         checkpoints[0] if checkpoints else "finetuned"
     )
 
-    with gr.Blocks(title="hamori — генератор гармонии") as demo:
+    with gr.Blocks(title="hamori — генератор аккордовых последовательностей") as demo:
         gr.Markdown(
-            "# hamori 🎶 — генератор гармонических периодов\n"
+            "# hamori 🎶 — генератор аккордовых последовательностей\n"
             "Заполните форму и нажмите **Сгенерировать**. "
             "Подробности — в разделе «Инструкция» внизу."
         )
@@ -255,7 +279,7 @@ def build_ui() -> gr.Blocks:
                     subdivision = gr.Radio([4, 8], value=4, label="Subdivision")
 
                 with gr.Row():
-                    auto_bars = gr.Checkbox(value=False, label="Авто (длина сама)")
+                    auto_bars = gr.Checkbox(value=False, label="Авто")
                     n_bars = gr.Slider(4, 16, value=8, step=1, label="Число тактов")
 
                 with gr.Accordion("Сэмплирование", open=True):
@@ -290,6 +314,10 @@ def build_ui() -> gr.Blocks:
             gr.Markdown(INSTRUCTIONS_RU)
 
         run.click(
+            fn=_begin_generation,
+            inputs=None,
+            outputs=[run, status, bars_out],
+        ).then(
             fn=generate,
             inputs=[
                 checkpoint, mode, key, style, function, time, subdivision,
@@ -297,6 +325,10 @@ def build_ui() -> gr.Blocks:
                 tonic_anchor, prefix_text, seed, tempo,
             ],
             outputs=[status, bars_out, chord_file, midi_file],
+        ).then(
+            fn=_end_generation,
+            inputs=None,
+            outputs=[run],
         )
 
     return demo