Merge codex's System Health and recovery work

Brings in panama-doctor (a 25-check diagnostic with fixture-backed
contracts), a Health service, a System Health page replacing Startup &
Services, and a bar indicator that stays absent until something is
actually degraded. All seven of its contracts pass on the merge.

Three things needed resolving rather than accepting:

The branch predates the debranding, so its user-visible strings still
named the product -- "Panama desktop is healthy", "Restart Panama",
"Panama tools". Rewritten to say the same thing without the name, which
is what the rest of the app now does.

Its Fedora hand-off card was a single button calling openGnomePanel
("network") under a subtitle naming five subjects. Main had already
replaced that with a row per subject, each opening the panel that owns
it, so those rows are ported into HealthPage instead. Printers and
online accounts stay on Network & Devices with the rest of the network
hardware.

That broke its own assertion, which matched the literal
openGnomePanel("network") string. Rewritten rather than reverted: it now
checks the boundary card exists and that every panel named in HealthPage
is one openGnomePanel actually allows, since a name outside the
allow-list opens nothing at all. Verified it catches a plausible-looking
wrong name.

SettingsShell and SettingsSidebar conflicted because both sides added
pages; resolved as the union, keeping its System Health page and live
footer alongside main's Mouse & Touchpad, Privacy & Security, Region &
Language and Online Accounts.

Claude-Session: https://claude.ai/code/session_01BRvzt4H8XXLPVH5MyYdk9L

config/dot/quickshell/modules/settings/SettingsShell.qml

@@ -11,6 +11,19 @@ Rectangle {
         && pageLoader.item.objectName === "home-phone-page"
         ? pageLoader.item.pageDiagnostics
         : ({})
+    readonly property var healthDiagnostics: pageLoader.status === Loader.Ready
+        && pageLoader.item
+        && pageLoader.item.objectName === "system-health-page"
+        ? pageLoader.item.uiDiagnostics()
+        : ({})
+
+    function requestHealthAction(id: string): bool {
+        if (pageLoader.status !== Loader.Ready
+                || !pageLoader.item
+                || pageLoader.item.objectName !== "system-health-page")
+            return false;
+        return pageLoader.item.activateRenderedAction(id);
+    }
 
     color: Theme.bg
     radius: 18
@@ -107,7 +120,7 @@ Rectangle {
             case "power": return powerPage;
             case "datetime": return dateTimePage;
             case "applications": return applicationsPage;
-            case "services": return servicesPage;
+            case "services": return healthPage;
             case "about": return aboutPage;
             default: return homePage;
             }
@@ -161,7 +174,7 @@ Rectangle {
     Component { id: privacyPage; PrivacyPage {} }
     Component { id: regionPage; RegionPage {} }
     Component { id: onlineAccountsPage; OnlineAccountsPage {} }
-    Component { id: servicesPage; ServicesPage {} }
+    Component { id: healthPage; HealthPage {} }
     Component { id: aboutPage; AboutPage {} }
 
     Shortcut {