Change main event loop to use label/goto

Save a level of nesting and mental bookkeeping. The control flow was
already jumping within and outside of the loop, so we aren't making this
any more complicated than it already was -- in fact, it's more simple,
because now we also don't have to remember that we're in a 'for' loop.

tui_main.c

@@ -3469,9 +3469,8 @@ int main(int argc, char **argv) {
 
   tui_restart_osc_udp_if_enabled(&t);
 
-  WINDOW *cont_window = NULL;
-
-  int key = KEY_RESIZE;
+  WINDOW *cont_window = NULL; // No window yet, wait for resize
+  int key = KEY_RESIZE;       // Make first event a resize
   wtimeout(stdscr, 0);
   int cur_timeout = 0;
   Usz bracketed_paste_starting_x = 0, bracketed_paste_y = 0,
@@ -3482,7 +3481,8 @@ int main(int argc, char **argv) {
   // Send initial BPM
   send_num_message(t.ged.oosc_dev, "/orca/bpm", (I32)t.ged.bpm);
 
-  for (;;) {
+  // Main loop. Process events as they arrive.
+event_loop:
   switch (key) {
   case ERR: {
     ged_do_stuff(&t.ged);
@@ -3632,8 +3632,7 @@ int main(int argc, char **argv) {
         delwin(cont_window);
       }
       wclear(stdscr);
-        cont_window =
-            derwin(stdscr, content_h, content_w, content_y, content_x);
+      cont_window = derwin(stdscr, content_h, content_w, content_y, content_x);
       t.ged.is_draw_dirty = true;
     }
     // We might do this once soon after startup if the user specified neither
@@ -3646,8 +3645,7 @@ int main(int argc, char **argv) {
       Usz new_field_h, new_field_w;
       if (tui_suggest_nice_grid_size(&t, content_h, content_w, &new_field_h,
                                      &new_field_w)) {
-          field_init_fill(&t.ged.field, (Usz)new_field_h, (Usz)new_field_w,
-                          '.');
+        field_init_fill(&t.ged.field, (Usz)new_field_h, (Usz)new_field_w, '.');
         mbuf_reusable_ensure_size(&t.ged.mbuf_r, new_field_h, new_field_w);
         ged_make_cursor_visible(&t.ged);
       } else {
@@ -3734,8 +3732,8 @@ int main(int argc, char **argv) {
         if (bracketed_paste_y < t.ged.field.height &&
             bracketed_paste_x < t.ged.field.width) {
           gbuffer_poke(t.ged.field.buffer, t.ged.field.height,
-                         t.ged.field.width, bracketed_paste_y,
-                         bracketed_paste_x, cleaned);
+                       t.ged.field.width, bracketed_paste_y, bracketed_paste_x,
+                       cleaned);
           // Could move this out one level if we wanted the final selection
           // size to reflect even the pasted area which didn't fit on the
           // grid.
@@ -4010,7 +4008,7 @@ int main(int argc, char **argv) {
     wtimeout(stdscr, 0);
     cur_timeout = 0;
   }
-  }
+  goto event_loop;
 quit:
   ged_stop_all_sustained_notes(&t.ged);
   qnav_deinit();