Recover model-usage limits from a boot-time probe failure

The shell starts before DHCP finishes, so Claude's first probe of the
OAuth usage endpoint came back as a transport failure and pinned "Claude
limits unavailable" for a full refresh interval. Opening the panel could
not clear it either: the open path refreshed unforced and hit the same
throttle it was trying to escape.

A transport failure now arms a short retry that goes straight to the
probe, since a retry answering to the throttle never gets off the
ground. Any real answer disarms it — a server that replied, 429
included, is one to stop pestering. Probes are single-flight, a fresh
token skips the throttle its predecessor set, and opening the panel asks
for the wire without re-walking every transcript on disk.

The module also earns its place in the bar now instead of sitting there
dimmed with nothing to say: it collapses out entirely until a provider
has actually recorded usage, here or on a synced machine. That made both
presence probes redundant, so they are gone. Selection follows the
provider rather than its slot, so one appearing while the panel is open
no longer swaps out what you were reading.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

shell/plugins/model-usage/Panel.qml

@@ -19,10 +19,16 @@ Panel {
   readonly property string fontFamily: bar ? bar.fontFamily : Style.font.family
 
   readonly property var providers: usage.enabledProviders
-  property int providerIndex: 0
-  readonly property var provider: providers.length > 0
-    ? providers[Math.max(0, Math.min(providerIndex, providers.length - 1))]
-    : null
+  // The selection follows the provider, not the slot it happens to sit in: a
+  // provider whose first scan lands while the panel is open would otherwise
+  // shift the list underneath you and swap out what you were reading.
+  property string selectedProviderId: ""
+  readonly property int providerIndex: {
+    for (var i = 0; i < providers.length; i++)
+      if (providers[i].providerId === selectedProviderId) return i
+    return 0
+  }
+  readonly property var provider: providers.length > 0 ? providers[providerIndex] : null
 
   property bool cursorActive: false
 
@@ -39,11 +45,9 @@ Panel {
   function alpha(c, a) { return Qt.rgba(c.r, c.g, c.b, a) }
 
   function selectProvider(index) {
-    if (providers.length === 0) {
-      providerIndex = 0
-      return
-    }
-    providerIndex = ((index % providers.length) + providers.length) % providers.length
+    if (providers.length === 0) return
+    var wrapped = ((index % providers.length) + providers.length) % providers.length
+    selectedProviderId = providers[wrapped].providerId
   }
 
   function refreshNow() {
@@ -317,16 +321,20 @@ Panel {
     return ""
   }
 
+  // Nothing to report, nothing in the bar: Bar.qml collapses a slot whose item
+  // is invisible, so the icon appears the moment the first scan finds usage and
+  // stays away entirely on a machine that has never run either CLI.
+  visible: providers.length > 0
   implicitWidth: button.implicitWidth
   implicitHeight: button.implicitHeight
 
-  onProvidersChanged: if (providerIndex >= providers.length) selectProvider(0)
   onProviderIndexChanged: if (panelFlick) panelFlick.contentY = 0
   onOpenedChanged: if (opened) {
     cursorActive = false
     nowMs = Date.now()
     if (panelFlick) panelFlick.contentY = 0
     usage.refreshAll()
+    usage.refreshLimits()
     Qt.callLater(function() { keyCatcher.forceActiveFocus() })
   }
 
@@ -361,7 +369,6 @@ Panel {
     bar: root.bar
     text: "󱚣"
     active: root.alarming
-    dimmed: root.providers.length === 0
     onPressed: function(buttonCode) {
       if (buttonCode === Qt.RightButton) root.refreshNow()
       else if (buttonCode === Qt.MiddleButton) root.selectProvider(root.providerIndex + 1)
@@ -441,7 +448,7 @@ Panel {
             visible: root.providers.length === 0
             width: parent.width
             topPadding: Style.space(24)
-            text: "No AI coding subscriptions found.\nClaude Code and Codex show up here once installed."
+            text: "No AI coding subscriptions found.\nClaude Code and Codex show up here once you've used them."
             color: root.dim
             font.family: root.fontFamily
             font.pixelSize: Style.font.body