feat(WP-0016/C1-C4): Layer 2 isolation and clean-base infrastructure

- Add Web/Controller/Prelude.hs (was missing; 8 controllers failed to import it)
- Add .ghci-core and scripts/compile-check-core to compile Layer 1+2 in
  isolation without loading Main.hs or any controller/view (Layer 3)
- Fix Application/Helper/BottleneckDetector.hs: replace coerce :: Id' -> UUID
  with unpackId (IHP Id' wraps a type family; Data.Coerce cannot cross it)
- Fix devenv.nix: add pkgs.nodePackages.tailwindcss so devenv process scripts
  find the tailwindcss binary (devenv v2 builds scripts with only local packages)

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

.ghci-core

@@ -0,0 +1,84 @@
+-- .ghci-core — loads ONLY Layer 1 (Generated.Types, Web.Types) and Layer 2
+-- (Application/Helper/*) for independent compilation verification.
+--
+-- Usage (inside devenv shell):
+--   ghci -ghci-script .ghci-core
+-- or:
+--   ghcid --command "ghci -ghci-script .ghci-core"
+--
+-- This file intentionally does NOT load Main.hs or any Web/Controller / Web/View
+-- modules. Once this reaches "Ok, N modules loaded" with no errors, the core
+-- layer is verified clean and Layer 3 errors are isolated to controllers/views.
+
+-- NOTE: we do NOT use :loadFromIHP applicationGhciConfig here because it ends
+-- with ":l Main.hs" which would load all of Layer 3.  Instead we duplicate
+-- the environment flags from applicationGhciConfig and load only core modules.
+:set -i.
+:set -iIHP/ihp-hsx
+:set -iConfig
+:set -ibuild
+:set -iIHP
+:set -XOverloadedStrings
+:set -XNoImplicitPrelude
+:set -XImplicitParams
+:set -XRank2Types
+:set -XDisambiguateRecordFields
+:set -XNamedFieldPuns
+:set -XDuplicateRecordFields
+:set -XOverloadedLabels
+:set -XFlexibleContexts
+:set -XTypeSynonymInstances
+:set -XFlexibleInstances
+:set -XQuasiQuotes
+:set -XTypeFamilies
+:set -XPackageImports
+:set -XScopedTypeVariables
+:set -XRecordWildCards
+:set -XTypeApplications
+:set -XDataKinds
+:set -XInstanceSigs
+:set -XDeriveGeneric
+:set -XMultiParamTypeClasses
+:set -XTypeOperators
+:set -XUndecidableInstances
+:set -Wno-unsafe -Wno-name-shadowing -Wno-monomorphism-restriction -Wno-safe -Wno-missing-local-signatures -Wno-missing-home-modules
+:set -XDeriveDataTypeable
+:set -XLambdaCase
+:set -XDefaultSignatures
+:set -XEmptyDataDeriving
+:set -XBangPatterns
+:set -XBlockArguments
+:set -XMultiWayIf
+:set -XFunctionalDependencies
+:set -package ihp
+:set -fbyte-code
+:set -j1
+:set -fkeep-going
+:set -Wno-partial-type-signatures
+:set -XPartialTypeSignatures
+:set -XStandaloneDeriving
+:set -XDerivingVia
+:set -XTemplateHaskell
+:set -XDeepSubsumption
+:set -XOverloadedRecordDot
+:set -Werror=missing-fields
+:set -fwarn-incomplete-patterns
+:set -package ghc
+:set -fno-warn-ambiguous-fields
+
+-- Layer 1: generated types and Web.Types
+:load build/Generated/Types.hs Web/Types.hs Web/Routes.hs
+
+-- Layer 2: helpers (order matters — imports within Layer 2 must be satisfied)
+:add Application/Helper/View.hs
+:add Application/Helper/Controller.hs
+:add Application/Helper/TypeRegistry.hs
+:add Application/Helper/ModelRouter.hs
+:add Application/Helper/RoutingEngine.hs
+:add Application/Helper/FrictionScore.hs
+:add Application/Helper/BottleneckDetector.hs
+:add Application/Helper/HubHealth.hs
+:add Application/Helper/CorrelationEngine.hs
+:add Application/Helper/CrossHubPropagation.hs
+:add Application/Helper/AgentBridge.hs
+:add Application/Helper/ApiRateLimit.hs

Application/Helper/BottleneckDetector.hs

@@ -8,7 +8,6 @@ import Generated.Types
 import Web.Routes ()
 import Data.Time.Clock (addUTCTime, getCurrentTime, NominalDiffTime)
 import Database.PostgreSQL.Simple (Only(..))
-import Data.Coerce (coerce)
 
 -- | Severity based on how much older than the threshold the record is.
 staleSeverity :: NominalDiffTime -> NominalDiffTime -> Text
@@ -47,7 +46,7 @@ detectBottlenecks hubId hubWidgets candidates requirements decisions deployments
             | c <- candidates
             , c.status == "open"
             , c.createdAt < addUTCTime (negate candidateThreshold) now
-            , c.id `notElem` map coerce existingSubjects
+            , unpackId c.id `notElem` existingSubjects
             ]
 
     -- Stage 2: requirements with no decision older than 60 days
@@ -57,7 +56,7 @@ detectBottlenecks hubId hubWidgets candidates requirements decisions deployments
             | r <- requirements
             , r.createdAt < addUTCTime (negate requirementThreshold) now
             , r.id `notElem` linkedReqIds
-            , r.id `notElem` map coerce existingSubjects
+            , unpackId r.id `notElem` existingSubjects
             ]
 
     -- Stage 3: decisions with no deployment older than 30 days
@@ -67,7 +66,7 @@ detectBottlenecks hubId hubWidgets candidates requirements decisions deployments
             | d <- decisions
             , d.decidedAt < addUTCTime (negate decisionThreshold) now
             , d.id `notElem` linkedDecisionIds
-            , d.id `notElem` map coerce existingSubjects
+            , unpackId d.id `notElem` existingSubjects
             ]
 
     -- Stage 4: deployments with no outcome signal older than 14 days
@@ -80,7 +79,7 @@ detectBottlenecks hubId hubWidgets candidates requirements decisions deployments
             | dep <- deployments
             , dep.deployedAt < addUTCTime (negate observationThreshold) now
             , not (any (\wid -> wid `elem` signalWids) widgetIdSet)
-            , dep.id `notElem` map coerce existingSubjects
+            , unpackId dep.id `notElem` existingSubjects
             ]
 
     let mkBottleneck stage subjType subjId stalledSince threshold = do
@@ -95,10 +94,10 @@ detectBottlenecks hubId hubWidgets candidates requirements decisions deployments
                 |> set #severity    severity
                 |> createRecord
 
-    r1 <- mapM (\(c, t) -> mkBottleneck "candidate"   "RequirementCandidate" (coerce c.id :: UUID) t candidateThreshold)   staleCandidates
-    r2 <- mapM (\(r, t) -> mkBottleneck "requirement" "Requirement"          (coerce r.id :: UUID) t requirementThreshold)  stalRequirements
-    r3 <- mapM (\(d, t) -> mkBottleneck "decision"    "DecisionRecord"       (coerce d.id :: UUID) t decisionThreshold)     staleDecisions
-    r4 <- mapM (\(d, t) -> mkBottleneck "observation" "DeploymentRecord"     (coerce d.id :: UUID) t observationThreshold)  staleDeployments
+    r1 <- mapM (\(c, t) -> mkBottleneck "candidate"   "RequirementCandidate" (unpackId c.id) t candidateThreshold)   staleCandidates
+    r2 <- mapM (\(r, t) -> mkBottleneck "requirement" "Requirement"          (unpackId r.id) t requirementThreshold)  stalRequirements
+    r3 <- mapM (\(d, t) -> mkBottleneck "decision"    "DecisionRecord"       (unpackId d.id) t decisionThreshold)     staleDecisions
+    r4 <- mapM (\(d, t) -> mkBottleneck "observation" "DeploymentRecord"     (unpackId d.id) t observationThreshold)  staleDeployments
 
     pure (r1 <> r2 <> r3 <> r4)
 

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 ()

devenv.nix

@@ -15,6 +15,10 @@
   # GHC parallel module compilation is capped via -j1 in .ghci instead.
   env.GHCRTS = "-A32m -M2g";
 
+  # Make tailwindcss available in process scripts (devenv v2 builds process
+  # scripts with only packages declared here, not from flake ihp.packages).
+  packages = [ pkgs.nodePackages.tailwindcss ];
+
   # Tailwind CSS watcher — not part of IHP's core devenv module.
   processes.tailwind.exec = "tailwindcss -c tailwind/tailwind.config.js -i ./tailwind/app.css -o static/app.css --watch=always";
 }

scripts/compile-check-core

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# scripts/compile-check-core
+#
+# Verify Layer 1 + Layer 2 compile cleanly in isolation — WITHOUT loading
+# any controller, view, or Main.hs. Use this to establish and confirm the
+# clean base before working on Layer 3 (controllers/views).
+#
+# Usage (inside devenv shell):
+#   scripts/compile-check-core         # interactive
+#   scripts/compile-check-core --bg    # write to log only
+#
+# Once this reports "Ok, N modules loaded" with no errors, the core is clean.
+set -euo pipefail
+LOGFILE="${IHUB_COMPILE_LOG:-/tmp/ihub-core-errors.txt}"
+: > "$LOGFILE"
+echo "[compile-check-core] Writing to $LOGFILE"
+exec ghcid \
+  --no-title \
+  --outputfile "$LOGFILE" \
+  --command "ghci -ghci-script .ghci-core"