fix(WP-0014/A2): close remaining pure-param and structural compilation errors

Convert all remaining `<- paramOrNothing / param / paramOrDefault /
currentUserOrNothing` monadic binds to `let` — these functions are pure
(ImplicitParams-based) in IHP v1.5, so `<-` is a type error in an IO
do-block.

Controllers fixed:
  AgentDelegations, AiGovernancePolicies, Annotations, ApiConsumers,
  CollectiveProposals, DecisionRecords, DeploymentRecords,
  HubCapabilityManifests, HubRoutingRules, InstitutionalKnowledge,
  OutcomeCorrelations, RequirementCandidates, TypeRegistries,
  WebhookSubscriptions, Widgets,
  Api/V2/{Annotations,InteractionEvents,Token}

WebhookSubscriptions: remove orphaned `Right () ->` case arm that was
left inside a bare `unless` block (structural parse error).

Also carries forward all in-progress fixes from the working tree:
  helpers (AgentBridge, ApiRateLimit, BottleneckDetector,
            CrossHubPropagation, FrictionScore),
  views (CanSelect instances, HSX lambda extraction, formFor wrappers),
  env/build (envrc GHCi perms, flake.nix Tailwind + GHC resource limits,
             static/app.css additional Tailwind output).

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

Application/Helper/FrictionScore.hs

@@ -9,7 +9,8 @@ import Web.Routes ()
 import Database.PostgreSQL.Simple (Only(..))
 import Data.Time.Clock (addUTCTime, getCurrentTime)
 import qualified Data.Aeson as A
-import qualified Data.HashMap.Strict as H
+import qualified Data.Aeson.KeyMap as KM
+import qualified Data.Aeson.Key as AK
 
 -- | Friction score formula (documented):
 --
@@ -85,9 +86,9 @@ applyAdaptiveWeights hubId annCount errCount isRegressed staleCount = do
     mConfig <- query @AdaptiveThresholdConfig
         |> filterWhere (#hubId, hubId)
         |> fetchOneOrNothing
-    let overrides = maybe mempty (.weightOverrides) mConfig
+    let overrides = maybe (A.object []) (.weightOverrides) mConfig
         w k def   = case overrides of
-            A.Object o -> case H.lookup k o of
+            A.Object o -> case KM.lookup (AK.fromText k) o of
                 Just (A.Number n) -> round (n * fromIntegral def) :: Int
                 _                 -> def
             _ -> def