Rebrand to Offscale and rework the panel header

Forked from omarchy.tailscale at the packaged commit (omarchy-dev
4.0.0.r1744.gf002044). The `tailscale` branch holds the pristine upstream
subtree history so upstream changes can still be merged in; `master` is
this fork.

- Rename the plugin to pastilhas.offscale: manifest id/name, moduleName
  and ipcTarget, and display strings. Deliberately NOT renamed: the
  lowercase "tailscale" CLI invocations, the TailscaleIPs/TailscaleIPv6
  JSON fields from `tailscale status --json`, and
  authorizeTailscaleOperator. Renaming those loads fine but silently
  breaks peer parsing.
- TailscaleIcon.qml -> OffscaleIcon.qml, now rendering offscale-logo.png
  instead of the 3x3 dot grid, keeping the crossed/warning states.
- Add OffscaleHero.qml: a copy of qs.Ui.PanelHero with a titleComponent
  slot, so the wordmark (offscale-text.png) can replace the title text.
  Otherwise byte-identical to the original, so it stays diffable.
- Drop the cycling hero phrases entirely - the array, the 2.8s timer and
  the metaOpacity fade.
- Show the local machine as a PeerRow of its own, so it gets the same
  layout and copy menu as tailnet peers. Adds `navigable` to PeerRow so
  that row stays out of the peers keyboard cursor.
- Enlarge the bar icon: BarIconButton pins its icon to opticalCanvas, so
  opticalSize/slotSize are overridden alongside iconSize.

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

OffscaleIcon.qml

@@ -0,0 +1,74 @@
+import QtQuick
+import qs.Commons
+import qs.Ui
+
+Item {
+  id: root
+
+  property real iconSize: Style.font.icon
+  property color color: Color.foreground
+  property color badgeColor: Color.urgent
+  property bool crossed: false
+  property bool warning: false
+
+  width: iconSize
+  height: iconSize
+  implicitWidth: iconSize
+  implicitHeight: iconSize
+
+  // The Offscale mark, replacing the stock 3x3 Tailscale dot grid.
+  //
+  // offscale-logo.png lives beside this file rather than being referenced from
+  // ~/projects, so the plugin stays self-contained and keeps working if that
+  // tree moves. It is the source PNG trimmed of its transparent margin, padded
+  // back to square so it centres, and scaled 1254 -> 256 (1.1 MB -> 77 KB).
+  //
+  // sourceSize caps the decode at 256 regardless of how large iconSize gets, so
+  // the bar slot never decodes more pixels than it needs; mipmap keeps the
+  // downscale to ~27px clean instead of aliased.
+  Image {
+    id: logo
+    anchors.fill: parent
+    source: Qt.resolvedUrl("offscale-logo.png")
+    sourceSize.width: 256
+    sourceSize.height: 256
+    fillMode: Image.PreserveAspectFit
+    smooth: true
+    mipmap: true
+    // Dim the mark when Tailscale is down, matching how the stock icon faded
+    // its inactive dots.
+    opacity: root.crossed ? 0.45 : 1.0
+  }
+
+  // Diagonal strike when disconnected.
+  Rectangle {
+    visible: root.crossed
+    anchors.centerIn: parent
+    width: parent.width * 1.22
+    height: Math.max(2, parent.height * 0.14)
+    radius: height / 2
+    color: root.color
+    rotation: -45
+  }
+
+  // "!" badge when a login is needed.
+  BorderSurface {
+    visible: root.warning
+    width: Math.max(7, parent.width * 0.42)
+    height: width
+    radius: width / 2
+    color: root.badgeColor
+    anchors.right: parent.right
+    anchors.bottom: parent.bottom
+    borderSpec: Border.flat(Color.popups.background, 1)
+
+    Text {
+      anchors.centerIn: parent
+      text: "!"
+      color: Color.background
+      font.family: Style.font.family
+      font.pixelSize: Math.max(6, parent.height * 0.72)
+      font.bold: true
+    }
+  }
+}