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>

Web/Controller/Health.hs

@@ -0,0 +1,7 @@
+module Web.Controller.Health where
+
+import Web.Controller.Prelude
+import Web.Types
+
+instance Controller HealthController where
+    action HealthAction = renderPlain "ok"

Web/Controller/Prelude.hs

@@ -0,0 +1,12 @@
+module Web.Controller.Prelude
+    ( module Web.Types
+    , module Generated.Types
+    , module IHP.Prelude
+    , module IHP.ControllerPrelude
+    ) where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ControllerPrelude
+import Web.Routes ()

Web/Controller/Probes.hs

@@ -0,0 +1,42 @@
+module Web.Controller.Probes where
+
+import Web.Controller.Prelude
+import Web.View.Probes.Index
+import Web.View.Probes.New
+import Web.View.Probes.Show
+import Web.View.Probes.Edit
+
+instance Controller ProbesController where
+    action ProbesAction = do
+        probes <- query @Probe |> fetch
+        render IndexView { .. }
+
+    action NewProbeAction = do
+        let probe = newRecord @Probe
+        render NewView { .. }
+
+    action ShowProbeAction { probeId } = do
+        probe <- fetch probeId
+        render ShowView { .. }
+
+    action CreateProbeAction = do
+        newRecord @Probe
+            |> fill @'["name"]
+            |> createRecord
+        redirectTo ProbesAction
+
+    action EditProbeAction { probeId } = do
+        probe <- fetch probeId
+        render EditView { .. }
+
+    action UpdateProbeAction { probeId } = do
+        probe <- fetch probeId
+        probe
+            |> fill @'["name"]
+            |> updateRecord
+        redirectTo ProbesAction
+
+    action DeleteProbeAction { probeId } = do
+        probe <- fetch probeId
+        deleteRecord probe
+        redirectTo ProbesAction