feat(T01): bootstrap IHP v1.5 project scaffold

Merged ihp-new generated scaffold into repo. Sets appName to inter-hub,
adds Nix flake with IHP inputs, devenv config, and standard IHP project
structure. Nix + ihp-new + direnv installed system-wide.

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

Application/Script/Prelude.hs

@@ -0,0 +1,12 @@
+module Application.Script.Prelude
+( module IHP.ControllerPrelude
+, module Generated.Types
+, module IHP.Prelude
+, module IHP.ScriptSupport
+)
+where
+
+import IHP.Prelude
+import IHP.ControllerPrelude
+import Generated.Types
+import IHP.ScriptSupport