Divergence meter: keep digits inside the tubes, close the domes

The tube was 56 px wide while its dome (radius 28) spans 57, so the dome
overshot the right wall by a pixel; tubes are now 57 px. The Nixie digits
at size 110 were up to 60 px wide (plus the 1 px glow) in a 55 px tube;
size 90 fits, and each digit is clipped to the inside of its glass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

esphome/el512-panel.yaml

@@ -207,7 +207,7 @@ font:
   # Steins;Gate pages (also use f_cp_mono, f_cp_code and f_ks_pixel)
   - file: "gfonts://Nixie One"
     id: f_sg_nixie
-    size: 110
+    size: 90
     glyphs: "0123456789."
   - file: "gfonts://Special Elite"
     id: f_sg_title