feat: minimal IHP scaffold — T01-T05, T08 of IRP-WP-0001

- flake.nix adapted from inter-hub: appName=ihp-railiance-probe, stripped to
  core packages, GHC 9.10.3 Bug 1+2 overlays carried verbatim (pname check
  updated to ihp-railiance-probe-models)
- IHP project scaffold: Main.hs, Config.hs, App.cabal, Setup.hs, Makefile
- Schema: probes table (id, name, created_at)
- Health endpoint: GET /healthz → "ok" (HealthController)
- Probes CRUD: ProbesController + 4 views (Index, New, Show, Edit)
- Hspec test suite: Test/ProbeControllerSpec covers /probes and /healthz
- Helm chart in chart/: deployment, service, ingress, secret templates
- devenv.nix, devenv.yaml, .ghci, tailwind config

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

chart/templates/ingress.yaml

@@ -0,0 +1,20 @@
+{{- if .Values.ingress.enabled }}
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: {{ .Release.Name }}
+  annotations:
+    kubernetes.io/ingress.class: traefik
+spec:
+  rules:
+    - host: {{ .Values.ingress.host }}
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: {{ .Release.Name }}
+                port:
+                  number: {{ .Values.service.port }}
+{{- end }}