feat(app): move generate button next to the output panels

The button sat at the bottom of a long form while results render in the
right column, forcing a scroll up/down on every run. Place it at the top
of the output column so repeated generation needs no scrolling.

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

app.py

@@ -300,10 +300,11 @@ def build_ui() -> gr.Blocks:
                                      label="Seed (пусто = случайно)")
                     tempo = gr.Number(value=90, precision=0, label="Tempo (BPM)")
 
-                run = gr.Button("Сгенерировать", variant="primary")
-
             # ---- Right: outputs -------------------------------------------
             with gr.Column(scale=1):
+                # Button lives with the outputs so repeated generation needs no
+                # scrolling back up to the form.
+                run = gr.Button("Сгенерировать", variant="primary")
                 status = gr.Markdown()
                 bars_out = gr.Textbox(label="Сетка аккордов", lines=10,
                                       interactive=False)