Add felhom-hub: multi-customer dashboard service

- Hub service receives reports from customer controllers
- SQLite store with 90-day retention and auto-prune
- REST API: POST /api/v1/report, GET /api/v1/customers
- Dark theme dashboard with status overview table
- Customer detail page with system, storage, containers, backup, health
- Bearer token auth for report ingest, bcrypt auth for dashboard
- K8s manifest for felhom-system namespace (Deployment, Service, Ingress, PVC)
- Dockerfile with multi-stage build

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

hub/go.mod

@@ -0,0 +1,23 @@
+module gitea.dooplex.hu/admin/felhom-hub
+
+go 1.24.0
+
+require (
+	golang.org/x/crypto v0.31.0
+	gopkg.in/yaml.v3 v3.0.1
+	modernc.org/sqlite v1.45.0
+)
+
+require (
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
+	golang.org/x/sys v0.37.0 // indirect
+	gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 // indirect
+	modernc.org/libc v1.67.6 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+)