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>

Test/Main.hs

@@ -0,0 +1,13 @@
+module Main where
+
+import Test.Hspec
+import IHP.Prelude
+import qualified Test.ProbeControllerSpec as ProbeController
+
+main :: IO ()
+main = hspec do
+    describe "Sanity" do
+        it "1 + 1 = 2" do
+            1 + 1 `shouldBe` (2 :: Int)
+
+    ProbeController.spec