docs: add ADRs 0043-0053 covering remaining architecture gaps

New ADRs:
- 0043: Cilium CNI and Network Fabric
- 0044: DNS and External Access Architecture
- 0045: TLS Certificate Strategy (cert-manager)
- 0046: Companions Frontend Architecture
- 0047: MLflow Experiment Tracking and Model Registry
- 0048: Entertainment and Media Stack
- 0049: Self-Hosted Productivity Suite
- 0050: Argo Rollouts Progressive Delivery
- 0051: KEDA Event-Driven Autoscaling
- 0052: Cluster Utilities (Spegel, Descheduler, Reloader, CSI-NFS)
- 0053: Vaultwarden Password Management

README updated with table entries and badge count (53 total).

README.md

@@ -8,7 +8,7 @@
 [![License](https://img.shields.io/badge/License-MIT-green)](LICENSE)
 
 <!-- ADR-BADGES-START -->
-![ADR Count](https://img.shields.io/badge/ADRs-42_total-blue?logo=bookstack) ![Accepted](https://img.shields.io/badge/accepted-41-brightgreen) ![Proposed](https://img.shields.io/badge/proposed-0-yellow)
+![ADR Count](https://img.shields.io/badge/ADRs-53_total-blue?logo=bookstack) ![Accepted](https://img.shields.io/badge/accepted-53-brightgreen)
 <!-- ADR-BADGES-END -->
 
 ## 📖 Quick Navigation
@@ -133,6 +133,17 @@ homelab-design/
 | 0040 | [OPA Gatekeeper Policy Framework](decisions/0040-opa-gatekeeper-policy-framework.md) | ✅ accepted | 2026-02-09 |
 | 0041 | [Falco Runtime Threat Detection](decisions/0041-falco-runtime-threat-detection.md) | ✅ accepted | 2026-02-09 |
 | 0042 | [Trivy Operator Vulnerability Scanning](decisions/0042-trivy-operator-vulnerability-scanning.md) | ✅ accepted | 2026-02-09 |
+| 0043 | [Cilium CNI and Network Fabric](decisions/0043-cilium-cni-network-fabric.md) | ✅ accepted | 2026-02-09 |
+| 0044 | [DNS and External Access Architecture](decisions/0044-dns-and-external-access.md) | ✅ accepted | 2026-02-09 |
+| 0045 | [TLS Certificate Strategy](decisions/0045-tls-certificate-strategy.md) | ✅ accepted | 2026-02-09 |
+| 0046 | [Companions Frontend Architecture](decisions/0046-companions-frontend-architecture.md) | ✅ accepted | 2026-02-09 |
+| 0047 | [MLflow Experiment Tracking and Model Registry](decisions/0047-mlflow-experiment-tracking.md) | ✅ accepted | 2026-02-09 |
+| 0048 | [Entertainment and Media Stack](decisions/0048-entertainment-media-stack.md) | ✅ accepted | 2026-02-09 |
+| 0049 | [Self-Hosted Productivity Suite](decisions/0049-self-hosted-productivity-suite.md) | ✅ accepted | 2026-02-09 |
+| 0050 | [Argo Rollouts Progressive Delivery](decisions/0050-argo-rollouts-progressive-delivery.md) | ✅ accepted | 2026-02-09 |
+| 0051 | [KEDA Event-Driven Autoscaling](decisions/0051-keda-event-driven-autoscaling.md) | ✅ accepted | 2026-02-09 |
+| 0052 | [Cluster Utilities and Optimization](decisions/0052-cluster-utilities-optimization.md) | ✅ accepted | 2026-02-09 |
+| 0053 | [Vaultwarden Password Management](decisions/0053-vaultwarden-password-management.md) | ✅ accepted | 2026-02-09 |
 <!-- ADR-TABLE-END -->
 
 ## 🔗 Related Repositories