v0.13.1: UI polish fixes round 2 (4 fixes)

- Fix 1: deploy-cross-drive card uses correct CSS vars (--bg-secondary, --border-color)
- Fix 2: Auto-generated env values — badge inline with label, remove copy buttons, muted readonly inputs
- Fix 3: Snapshot table shows 0 instead of n/a; remove unused .col-na CSS
- Fix 4: Disk warnings moved inline under storage bars (Inline alert field, GetInlineAlerts, inline-warning CSS)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

controller/internal/web/handlers.go

@@ -124,6 +124,10 @@ func (s *Server) dashboardHandler(w http.ResponseWriter, _ *http.Request) {
 		data["CrossDriveFailed"] = crossDriveFailed
 	}
 
+	if s.alertManager != nil {
+		data["DiskWarnings"] = s.alertManager.GetInlineAlerts("dashboard")
+	}
+
 	s.render(w, "dashboard", data)
 }
 
@@ -363,6 +367,7 @@ func (s *Server) monitoringHandler(w http.ResponseWriter, _ *http.Request) {
 	// On monitoring page, exclude the "pings-missing" alert since the detailed table is visible
 	if s.alertManager != nil {
 		data["Alerts"] = s.alertManager.GetAlerts("pings-missing")
+		data["DiskWarnings"] = s.alertManager.GetInlineAlerts("monitoring")
 	}
 
 	// Ping status section