Add plain Kubernetes deployment manifests

[fenio]

Adds dependency-free Kubernetes manifests under deploy/kubernetes/ so Rackpad can be run on any cluster without Helm, an operator, or a third-party chart — just kubectl apply -k deploy/kubernetes/.

What's included

File	Purpose
namespace.yaml	rackpad namespace
pvc.yaml	2Gi RWO volume for the SQLite DB at /data
deployment.yaml	Single-replica, non-root (uid 10001), read-only-rootfs deployment with /api/health probes
service.yaml	ClusterIP on port 3000
ingress.yaml	Optional ingress example (commented defaults)
kustomization.yaml	Bundles the core resources
README.md	Quick start, env vars, discovery networking notes

Design

Mirrors the conventions in docker-compose.yml: single replica (SQLite is single-writer, strategy: Recreate), non-root, read-only root filesystem with a writable /tmp emptyDir, and the database persisted on a PVC. Probes hit the existing /api/health endpoint.

The README also documents the discovery networking tradeoffs on Kubernetes — L3 (ICMP/TCP/SNMP) works from a normal pod with NET_RAW, while L2/ARP MAC capture needs hostNetwork: true + NET_ADMIN (the equivalent of docker-compose.host-discovery.yml). Defaults stay minimal-privilege; raw caps are an opt-in documented step.

Validated with kubectl kustomize and kubectl apply --dry-run=client. Image tag left at :latest with a note to pin for production.

Happy to adjust paths, naming, or fold this into the docs differently if you'd prefer.

[Kobii-git]

Thanks so much for taking the time to contribute and open this pull request. I really appreciate the effort and the interest in improving Rackpad.

At this stage, I’m not accepting pull requests directly so I can maintain the integrity, consistency, and direction of the project while it is still moving quickly. For now, the best way to contribute is to open an issue describing the change, bug, or improvement you had in mind.

I’ll review issues, implement the changes in the main codebase where they fit, and then you’re very welcome to test the result, give feedback, and help refine it from there.

Thanks again for the contribution and for understanding.

[fenio]

I completely don't understand your rationale but after all it's your project. Do whatever you think is right ;)