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/qmldir

@@ -10,7 +10,9 @@ DisplaysPage 1.0 DisplaysPage.qml
 HomePage 1.0 HomePage.qml
 NotificationsPage 1.0 NotificationsPage.qml
 ScreenIntelligencePage 1.0 ScreenIntelligencePage.qml
-ServicesPage 1.0 ServicesPage.qml
+HealthPage 1.0 HealthPage.qml
+HealthSummary 1.0 HealthSummary.qml
+HealthCheckRow 1.0 HealthCheckRow.qml
 SettingRow 1.0 SettingRow.qml
 SettingsCard 1.0 SettingsCard.qml
 SettingsButton 1.0 SettingsButton.qml