New app icon, brand yellow, and bar-icon size compensation

- Replace the mark with OffScaleAppIcon.png, run through the same pipeline
  as before: trim the transparent margin, pad to square, scale to 256x256
  (654 KB -> 62 KB). One asset, two render sites.

- Retune the accent to #FCC001, the modal hexagon fill of the new icon.
  Sampled from fully-opaque pixels only — the yellows cluster at
  252,192-196,1-2, so this is the flat colour and not an antialiased edge.
  (`magick -alpha off` flattens onto black and gives a wrong answer here.)
  Replaces #FAE204 from the previous logo, which was noticeably greener.
  All three yellows — the bar's tailnet label, the active connection name,
  and the IP/DNS subtitle — resolve through root.accent, so this is one
  value.

- Hold the bar mark at 32px now that shell base-size is 24 rather than 20.
  Every size in the shell is a multiple of fontScale, so raising base-size
  to enlarge the stock bar icons would have scaled this one identically and
  left the relative gap unchanged; the icon/canvas/slot values are scaled
  down to compensate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Panel.qml

@@ -29,12 +29,17 @@ Panel {
   readonly property color urgent: bar ? bar.urgent : Color.urgent
   readonly property color dim: Qt.darker(foreground, 1.55)
 
-  // Brand yellow, sampled as the dominant opaque colour of offscale-logo.png.
+  // Brand yellow: the modal fill of the hexagons in OffScaleAppIcon.png,
-  // Used for exactly one thing: the IP / DNS subtitle under each machine, at
+  // sampled from fully-opaque pixels only (the cluster sits at 252,192-196,1-2,
-  // full strength. Stock renders that line through `dim`, but darkening yellow
+  // so this is the flat colour rather than an antialiased edge). Replaced
-  // shifts its hue to olive (#A19203) rather than merely quietening it, so it
+  // #FAE204, which came from the previous logo and was noticeably greener.
-  // gets the flat accent instead. Icons stay on the themed foreground.
+  //
-  readonly property color accent: "#FAE204"
+  // Everything yellow in the plugin resolves through here: the tailnet label in
+  // the bar, the active connection's name, and the IP / DNS subtitle under each
+  // machine. That subtitle takes the accent flat rather than through `dim`,
+  // because darkening yellow shifts its hue to olive rather than quietening it.
+  // Icons stay on the themed foreground.
+  readonly property color accent: "#FCC001"
   readonly property string fontFamily: bar ? bar.fontFamily : Style.font.family
   readonly property bool showConnections: tailscale.accounts.length > 1 || tailscale.accountsAccessDenied
   readonly property bool showPeers: tailscale.active && tailscale.peers.length > 0
@@ -438,8 +443,8 @@ Panel {
     // Style.bar.iconCanvas (16 * fontScale ~= 27px here). Growing iconSize
     // alone can't get past that box, so widen the canvas first. slotSize is
     // raised to match so the widget still reserves room for it in the bar.
-    opticalSize: Style.space(21)
+    opticalSize: Style.space(18)
-    slotSize: Style.space(23)
+    slotSize: Style.space(19)
     iconComponent: Component {
       Item {
         OffscaleIcon {
@@ -447,7 +452,7 @@ Panel {
           // Stock was space(11) = 18px at base-size 20 — noticeably smaller
           // than the neighbouring widgets. space(19) ~= 32px, inside the
           // widened canvas above. centerIn means it grows from the centre.
-          iconSize: Style.space(19)
+          iconSize: Style.space(16)
           color: root.barIconColor
           badgeColor: root.urgent
           crossed: !tailscale.active && !tailscale.needsLogin