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>

App.cabal

@@ -0,0 +1,57 @@
+-- Stub cabal file — only for HLS/tooling support. Not used by the build.
+-- See flake.nix for actual package management.
+name:                App
+version:             0.1.0.0
+license:             AllRightsReserved
+license-file:        LICENSE
+author:              Developers
+maintainer:          developers@example.com
+build-type:          Simple
+cabal-version:       >=1.10
+
+executable App
+  main-is:             Main.hs
+  build-depends:
+    ihp,
+    base,
+    wai,
+    text,
+    hspec,
+    ihp-hspec
+  hs-source-dirs:      .
+  default-language:    Haskell2010
+  extensions:
+    OverloadedStrings
+    , NoImplicitPrelude
+    , ImplicitParams
+    , Rank2Types
+    , DisambiguateRecordFields
+    , NamedFieldPuns
+    , DuplicateRecordFields
+    , OverloadedLabels
+    , FlexibleContexts
+    , TypeSynonymInstances
+    , FlexibleInstances
+    , QuasiQuotes
+    , TypeFamilies
+    , PackageImports
+    , ScopedTypeVariables
+    , RecordWildCards
+    , TypeApplications
+    , DataKinds
+    , InstanceSigs
+    , DeriveGeneric
+    , MultiParamTypeClasses
+    , TypeOperators
+    , DeriveDataTypeable
+    , MultiWayIf
+    , UndecidableInstances
+    , BlockArguments
+    , PartialTypeSignatures
+    , LambdaCase
+    , DefaultSignatures
+    , EmptyDataDeriving
+    , BangPatterns
+    , FunctionalDependencies
+    , StandaloneDeriving
+    , DerivingVia