Re-enable base jitter capped to +-1px; speed up bursts, shorten pauses

Re-enabled _glitch_base_jitter per request, but capped the shift to
+-1px instead of splitting the difference between the two bands' own
(larger) shift values -- a full-frame shift reads very differently than
a thin band shifting, so it needed to stay subtle. Confirmed no black
border across a full worst-case render (strong zoom, random position,
all 200 frames, all four corners).

Also sped up the RGB-split jitter (GLITCH_HOLD_TICKS 5 -> 2, ~100ms per
state) and shortened the pause between bursts (GLITCH_PAUSE_TICKS
15 -> 3, ~150ms). Payload stayed comfortably under budget despite both
changes adding more distinct frames to encode: 355KB worst case (strong
zoom + random position), vs. the 460KB device limit.

subwave_nowplaying.star

@@ -370,8 +370,8 @@ def _zoom_transformation(art_bytes, zoom_scale, zoom_position, subsonic_id):
 # (top/height as a fraction of ART_SLOT) are loosely modeled on the one
 # keyframe that was visible: roughly the top third and an overlapping
 # middle band, each about 30% of the frame's height.
-GLITCH_HOLD_TICKS = 5  # ~250ms per jitter state at the default 50ms/tick
-GLITCH_PAUSE_TICKS = 15  # ~750ms of clean art between bursts
+GLITCH_HOLD_TICKS = 2  # ~100ms per jitter state at the default 50ms/tick
+GLITCH_PAUSE_TICKS = 3  # ~150ms of clean art between bursts
 GLITCH_STATES_PER_CYCLE = 4
 
 # A larger pool than any one burst needs, so repeated cycles (see
@@ -480,14 +480,14 @@ def _glitch_jitter(zoom):
     sequence = []
     for cycle_index in range(GLITCH_REPEATS):
         for top1, h1, shift1, hue1, top2, h2, shift2, hue2 in _glitch_states_for_cycle(cycle_index):
-            # The art itself nudging along with the bands (not just the
-            # bands moving over a static image) was tried here via
-            # _glitch_base_jitter, splitting the difference between the
-            # two bands' own shift values -- commented out, not deleted,
-            # pending a call on whether it's actually working well.
-            # base_shift = int((shift1 + shift2) / 2.0)
+            # The art itself nudges along with the bands, not just the
+            # bands moving over a static image. Capped to +-1px (rather
+            # than splitting the difference between the two bands' own,
+            # larger shift values) -- a full-frame shift reads very
+            # differently than a thin band shifting, so it stays subtle.
+            base_shift = max(-1, min(1, int((shift1 + shift2) / 2.0)))
             state = render.Stack(children = [
-                # _glitch_base_jitter(zoom, base_shift),
+                _glitch_base_jitter(zoom, base_shift),
                 _glitch_band(zoom, top1, h1, shift1, hue1),
                 _glitch_band(zoom, top2, h2, shift2, hue2),
             ])