feat(hub): app telemetry analytics dashboard (v0.4.0)

- store/telemetry.go: new app_telemetry + app_log_issues tables with
  SaveAppTelemetry, GetFleetAppSummary (with P95), GetAppTelemetryHistory,
  GetAppCustomerBreakdown, GetCustomerAppSummary, GetAppIssues, prune methods
- api/handler.go: parse and save optional app_telemetry from report body,
  backward-compatible with old controllers
- cmd/hub/main.go: prune app_telemetry (90d) and stale issues (30d)
- web/apps.go: handleApps + handleAppDetail + chart data aggregation helpers
- web/server.go: routes for /apps, /apps/{name}, /static/chart.min.js;
  added memoryColor/accuracyClass/gt template functions
- web/embed.go: embed static/chart.min.js
- web/configs.go: add app telemetry section to handleCustomerUnified
- templates/apps.html: fleet-wide app list with summary cards and sortable table
- templates/app_detail.html: per-app page with Chart.js memory trend,
  customer breakdown, and known issues table
- templates/customer_unified.html: new Alkalmazás telemetria card
- templates/style.css: badge, summary-card, chart, period-selector,
  accuracy-dot, mem-color, data-table styles
- All templates: added Alkalmazások nav link

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

hub/internal/web/configs.go

@@ -233,6 +233,8 @@ func (s *Server) handleCustomerUnified(w http.ResponseWriter, r *http.Request, c
 	var events []store.Event
 	var eventCounts map[string]int
 
+	var appTelemetry []store.CustomerAppSummary
+
 	if customer != nil {
 		history, _ = s.store.GetCustomerHistory(customerID, 24*time.Hour)
 		notifPrefs, _ = s.store.GetNotificationPrefs(customerID)
@@ -243,6 +245,7 @@ func (s *Server) handleCustomerUnified(w http.ResponseWriter, r *http.Request, c
 		}
 		events, _ = s.store.GetRecentEvents(customerID, 50)
 		eventCounts, _ = s.store.CountEventsBySeverity(customerID, time.Now().Add(-24*time.Hour))
+		appTelemetry, _ = s.store.GetCustomerAppSummary(customerID, time.Now().Add(-7*24*time.Hour))
 	}
 
 	type pageData struct {
@@ -277,6 +280,9 @@ func (s *Server) handleCustomerUnified(w http.ResponseWriter, r *http.Request, c
 		Events      []store.Event
 		EventCounts map[string]int // severity → count (last 24h)
 
+		AppTelemetry    []store.CustomerAppSummary
+		HasAppTelemetry bool
+
 		Flash     string
 		ActiveNav string
 		CSRFField template.HTML
@@ -315,6 +321,9 @@ func (s *Server) handleCustomerUnified(w http.ResponseWriter, r *http.Request, c
 		Events:      events,
 		EventCounts: eventCounts,
 
+		AppTelemetry:    appTelemetry,
+		HasAppTelemetry: len(appTelemetry) > 0,
+
 		Flash:     r.URL.Query().Get("flash"),
 		ActiveNav: "configs",
 		CSRFField: s.csrfField(r),