Make album art zoom and color scheme configurable

Zoom level is a dropdown (Off/Subtle/Moderate/Strong) controlling how far
the album art zooms in during its breathing effect; Off skips the
animation.Transformation entirely and just shows a static crop.

Color schemes now match SUB/WAVE's own web UI theme picker (Blueprint,
Classic Dark, Classic Light, Cyberpunk, Flare, Recon, Signal, Vinyl) so a
station can mirror its own site theme on the device, including a
background fill that was previously hardcoded to black.

README.md

@@ -4,9 +4,7 @@ Tronbyt/Tidbyt app showing the current track on a [SUB/WAVE](https://github.com/
 internet radio station: album art with a slow zoom/pan reveal, and four
 scrolling lines — track title/artist, a thin separator, the current show
 and host, and local time/temperature — plus a track progress bar pinned to
-the bottom of the 32px-wide text column. Color scheme (cyan title/artist,
-white show name, magenta host/progress bar) is loosely modeled on SUB/WAVE's
-own web now-playing display.
+the bottom of the 32px-wide text column.
 
 Not tied to any specific station — set your own station's base URL in the
 app's config when adding it to a device.
@@ -17,6 +15,14 @@ app's config when adding it to a device.
   `https://radio.example.com`. No trailing slash needed (stripped
   automatically). No auth required — SUB/WAVE's now-playing and cover-art
   endpoints are public.
+- **Color scheme** — matches SUB/WAVE's own web UI theme picker (Blueprint,
+  Classic Dark, Classic Light, Cyberpunk, Flare, Recon, Signal, Vinyl), so
+  the device can mirror your station's own site theme. Defaults to
+  Cyberpunk. Each theme sets a background fill, the main text color
+  (title/artist/show), an accent (host/DJ name + progress bar fill), and a
+  muted color for the time/temp line.
+- **Album art zoom** — how far the album art's breathing zoom effect goes
+  in: Off, Subtle, Moderate (default), or Strong.
 
 ## How it works