feat(patterns): add expanded animation pack with smoke tests

Add a broad set of new pattern modules and matching pattern smoke scripts so the new effects can be validated directly on-device.

src/patterns/gradient_scroll.py

@@ -0,0 +1,57 @@
+import utime
+
+
+class GradientScroll:
+    def __init__(self, driver):
+        self.driver = driver
+
+    def _render(self, colors, phase, brightness):
+        num_leds = self.driver.num_leds
+        color_count = len(colors)
+        if num_leds <= 0 or color_count <= 0:
+            return
+        if color_count == 1:
+            self.driver.fill(self.driver.apply_brightness(colors[0], brightness))
+            return
+
+        full_span = color_count * 256
+        phase_shift = (phase * full_span) // 256
+        for i in range(num_leds):
+            pos = ((i * full_span) // num_leds + phase_shift) % full_span
+            idx = pos // 256
+            frac = pos & 255
+
+            c1 = colors[idx]
+            c2 = colors[(idx + 1) % color_count]
+            blended = (
+                c1[0] + ((c2[0] - c1[0]) * frac) // 256,
+                c1[1] + ((c2[1] - c1[1]) * frac) // 256,
+                c1[2] + ((c2[2] - c1[2]) * frac) // 256,
+            )
+            self.driver.n[i] = self.driver.apply_brightness(blended, brightness)
+        self.driver.n.write()
+
+    def run(self, preset):
+        """Scrolling blended gradient.
+
+        n1: phase step amount (default 1)
+        """
+        colors = preset.c if preset.c else [(255, 0, 0), (0, 0, 255)]
+        phase = self.driver.step % 256
+        step_amount = max(1, int(preset.n1) if int(preset.n1) > 0 else 1)
+        last_update = utime.ticks_ms()
+
+        while True:
+            delay_ms = max(1, int(preset.d))
+            now = utime.ticks_ms()
+            if utime.ticks_diff(now, last_update) >= delay_ms:
+                self._render(colors, phase, preset.b)
+                phase = (phase + step_amount) % 256
+                self.driver.step = phase
+                last_update = utime.ticks_add(last_update, delay_ms)
+
+                if not preset.a:
+                    yield
+                    return
+
+            yield