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/store/store.go

@@ -148,6 +148,53 @@ func (s *Store) migrate() error {
 	// v0.3.0: add channel column to notification_log (idempotent)
 	s.db.Exec("ALTER TABLE notification_log ADD COLUMN channel TEXT NOT NULL DEFAULT 'customer'")
 
+	// v0.4.0: app telemetry tables
+	_, err = s.db.Exec(`
+		CREATE TABLE IF NOT EXISTS app_telemetry (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			customer_id TEXT NOT NULL,
+			app_name TEXT NOT NULL,
+			display_name TEXT NOT NULL DEFAULT '',
+			reported_at DATETIME NOT NULL,
+			memory_current_mb REAL DEFAULT 0,
+			memory_avg_mb REAL DEFAULT 0,
+			memory_peak_mb REAL DEFAULT 0,
+			cpu_avg_percent REAL DEFAULT 0,
+			catalog_estimate TEXT DEFAULT '',
+			catalog_limit TEXT DEFAULT '',
+			log_errors INTEGER DEFAULT 0,
+			log_warnings INTEGER DEFAULT 0,
+			containers_json TEXT DEFAULT '[]',
+			issues_json TEXT DEFAULT '[]'
+		);
+
+		CREATE INDEX IF NOT EXISTS idx_app_telemetry_lookup
+			ON app_telemetry(app_name, reported_at);
+		CREATE INDEX IF NOT EXISTS idx_app_telemetry_customer
+			ON app_telemetry(customer_id, app_name, reported_at);
+		CREATE INDEX IF NOT EXISTS idx_app_telemetry_prune
+			ON app_telemetry(reported_at);
+
+		CREATE TABLE IF NOT EXISTS app_log_issues (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			app_name TEXT NOT NULL,
+			fingerprint TEXT NOT NULL,
+			severity TEXT NOT NULL,
+			message TEXT NOT NULL,
+			first_seen DATETIME NOT NULL,
+			last_seen DATETIME NOT NULL,
+			occurrence_count INTEGER DEFAULT 1,
+			affected_customers TEXT DEFAULT '[]',
+			UNIQUE(app_name, fingerprint)
+		);
+
+		CREATE INDEX IF NOT EXISTS idx_app_log_issues_app
+			ON app_log_issues(app_name, last_seen DESC);
+	`)
+	if err != nil {
+		return err
+	}
+
 	return nil
 }