feat(waybar): drop redundant network module, enlarge power-profile glyph

The network/wifi indicator duplicated nm-applet, which already sits in the
tray (services.network-manager-applet.enable), so remove it from the bar.
And the power-profile speedometer glyph rendered noticeably smaller than
the neighbouring indicators, so bump its font-size (+3pt generated; 20px
summer-day, 17px summer-night).

Applied to the generated bar (waybar.nix) and both whole-swap themes
(summer-day/night waybar.{jsonc,css}) for parity.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

themes/summer-day/waybar.jsonc

@@ -11,7 +11,7 @@
 
   "modules-left": ["custom/launcher", "clock", "clock#date"],
   "modules-center": ["hyprland/workspaces"],
-  "modules-right": ["pulseaudio", "network", "custom/powerprofile", "battery", "tray", "custom/notification", "custom/powermenu"],
+  "modules-right": ["pulseaudio", "custom/powerprofile", "battery", "tray", "custom/notification", "custom/powermenu"],
 
   "hyprland/workspaces": {
     "disable-scroll": true,
@@ -46,14 +46,6 @@
     "tooltip-format": "Playing at {volume}%"
   },
 
-  "network": {
-    "format-wifi": " {signalStrength}%",
-    "format-ethernet": "",
-    "format-disconnected": "󰤭",
-    "on-click": "sh -c '$TERMINAL -e nmtui'",
-    "tooltip-format": "{ipaddr} via {gwaddr}"
-  },
-
   "battery": {
     "interval": 60,
     "states": { "warning": 30, "critical": 15 },