feat(patterns): align manual and auto behaviour

Unify manual/auto timing semantics for key patterns, add preset background support, and improve runtime observability while keeping the driver responsive under beat-triggered selects.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/patterns/pulse.py

@@ -14,6 +14,12 @@ class Pulse:
         self.driver.fill(self.driver.apply_brightness(bg_base, preset.b))
 
         color_index = self.driver.step % max(1, len(colors))
+        if not preset.a:
+            # Manual / beat trigger: each select restarts this generator and resets
+            # cycle_start below. Advancing step here makes each beat the next colour
+            # without requiring a full wall-clock cycle between beats.
+            nclr = max(1, len(colors))
+            self.driver.step = (color_index + 1) % nclr
         cycle_start = utime.ticks_ms()
 
         # State machine based pulse using a single generator loop
@@ -52,13 +58,13 @@ class Pulse:
                 # Delay phase: LEDs off between pulses
                 self.driver.fill(bg_color)
             else:
-                # End of cycle, move to next color and restart timing
+                # End of cycle: auto advances colour and loops; manual already
+                # advanced step at run start for the next beat.
+                if not preset.a:
+                    break
                 color_index = (color_index + 1) % max(1, len(colors))
                 self.driver.step = color_index
                 cycle_start = now
-                if not preset.a:
-                    break
-                # Skip drawing this tick, start next cycle
                 yield
                 continue