feat(libredb-studio): add LibreDB Studio application chart

[cevheri]

Adds charts/libredb-studio, an application chart for LibreDB Studio, an open-source web SQL IDE. Follows up on libredb/libredb-studio#1183, where listing it here was suggested.

One pod, no subcharts. Studio keeps its own data (saved connections, queries, history) in SQLite on a PVC, so a first install needs no settings.

A few choices worth a look:

• The admin password and JWT_SECRET are generated once into a Secret and read back with lookup. JWT_SECRET also seals the saved connection passwords, so the Secret and the PVC both carry helm.sh/resource-policy: keep.
• replicas: 1 with Recreate, because of SQLite on a ReadWriteOnce volume.
• The session cookie is Secure, so plain http on a host other than localhost loops at login. auth.insecureCookie is an explicit opt-in, and NOTES warns when the ingress has no TLS.
• Studio has no /metrics, so the two alerts read kube-state-metrics. The rule sets release: prometheus directly; the shared label helper would override it.
• The icon points at our repo (192 px PNG). Feel free to mirror it into your bucket.

Tested on k3d (Kubernetes 1.35) with kube-prometheus-stack and Helm 3.19:

• helm lint --strict clean; default install 1/1 Running, 0 restarts
• saved a PostgreSQL connection in the browser and queried it; it still worked after a pod restart, an upgrade, and an uninstall plus reinstall, each time with an empty browser
• both alert rules load, and the down alert goes pending at 0 replicas
• ingress over plain http: login loops by default and works with auth.insecureCookie=true
• index regenerated: one entry added, no other digest changed

[cevheri]

Hi all, any update this PR
@arunesh-j, @PiyushSingh-ZS

[cevheri]

this guy is your team ? : libredb/libredb-studio#1183 (comment)