Rework the CONNECTIONS section

- Label each connection with its tailnet and account rather than the
  nickname alone. `tailscale switch --list --json` carries both, and on a
  multi-tailnet setup the nickname is the least useful field — "andre"
  says nothing about which tailnet you would be switching to. Renders as
  "headscale.pertento.ai (andre)", falling back through tailnet, then
  account, then profile id when a field is missing.

- Mark the active connection with colour instead of a filled background:
  brand yellow on its label, currentFill cleared. The theme sets
  selected-border-width to 0, so clearing the fill leaves nothing drawn.
  Hover still highlights through `fill`, so the row keeps its affordance.
  Exit-node and Mullvad-region rows are untouched and still fill.

- Sort the active connection to the top. Done in parseAccounts rather
  than at render time: the keyboard cursor indexes into
  tailscale.accounts, so sorting only in the view would leave j/k acting
  on a different row than the highlighted one. Array.sort is stable, so
  the remaining profiles keep the CLI's order.

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

Panel.qml

@@ -854,7 +854,12 @@ Panel {
     current: selectedAccount
     foreground: root.foreground
     fill: root.hoverFill
-    currentFill: root.selectedFill
+    // No filled background on the active connection — it reads as the brand
+    // yellow on its label instead (see the Text below). `current` also selects
+    // the "selected" border spec, but the theme sets selected-border-width to
+    // 0, so clearing the fill leaves nothing drawn. Hover still highlights
+    // through `fill`, so the row keeps its affordance.
+    currentFill: "transparent"
 
     implicitHeight: accountInner.implicitHeight + Style.spacing.xl
 
@@ -888,7 +893,9 @@ Panel {
 
       Text {
         text: accountRow.accountText
-        color: root.foreground
+        // The active connection is marked by colour rather than a filled
+        // background: brand yellow here, themed white for the others.
+        color: accountRow.selectedAccount ? root.accent : root.foreground
         font.family: root.fontFamily
         font.pixelSize: Style.font.body
         font.bold: accountRow.selectedAccount