grafana: deploy Grafana instance, datasource and dashboards (#238)

## Why
Deploys Grafana in-cluster (observability project) via the grafana-operator, mirroring the puppet Grafana but modernised — **CNPG** for state, **Authentik OIDC** for auth — and ports the live datasource + dashboards in as CRs.

Depends on: grafana-operator (#235, merged), grafana schemas (#236, merged), Authentik OIDC (terraform-authentik #2), Vault seeds (done), and `^grafana/` image proxy (terraform-artifactapi #5).

## Changes (`apps/base/grafana`)
- **CNPG** postgres Cluster + rw Pooler (db `grafana`); **VaultAuth** + **VaultStaticSecrets** pulling `postgres`/`oauth` credentials from `kv/kubernetes/namespace/grafana/default/*`.
- **Grafana CR**: postgres backend via the pooler; Authentik `generic_oauth` (client id/secret from the Vault-synced secret, openid/email/profile scopes, group→role mapping); `root_url` grafana.k8s.syd1.au.unkin.net.
- **1 GrafanaDatasource** — k8s VictoriaMetrics via the operator `vmselect-main` service; reuses the previous default datasource uid so the imported dashboards resolve unedited.
- **13 GrafanaDashboards** (gzipJson) exported from the current grafana.
- **Gateway API** (traefik-internal) + HTTPRoute for grafana.k8s.syd1.au.unkin.net.
- Registered in the observability ApplicationSet + project.

## Review notes
- OAuth `role_attribute_path` maps Authentik group `grafana-admins` → Admin, else Viewer — **confirm the group name**.
- `database.ssl_mode: require` against the CNPG pooler — adjust if the pooler isn't serving TLS.
- The `VictoriaLogs - cluster` dashboard has no in-cluster logs datasource yet (no VictoriaLogs in k8s) — included for completeness, will be empty until one exists.
- `make kubeconform` clean (24 resources, validated against the strict grafana schemas).

Reviewed-on: #238
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/grafana/dashboards/gitea.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: grafana.integreatly.org/v1beta1
+kind: GrafanaDashboard
+metadata:
+  name: gitea
+  namespace: grafana
+spec:
+  instanceSelector:
+    matchLabels:
+      dashboards: "grafana"
+  resyncPeriod: 5m
+  allowCrossNamespaceImport: false
+  gzipJson: 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