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>

Web/Controller/InstitutionalKnowledge.hs

@@ -2,7 +2,10 @@ module Web.Controller.InstitutionalKnowledge where
 
 -- IHF Phase 12 — Platform Memory (IHUB-WP-0013 T05)
 
-import Web.Controller.Prelude
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ControllerPrelude
 import Web.View.InstitutionalKnowledge.Index
 import Web.View.InstitutionalKnowledge.Show
 import IHP.ModelSupport (sqlQuery)
@@ -27,8 +30,8 @@ instance Controller InstitutionalKnowledgeController where
         render ShowView { entry, hub, mDecision }
 
     action QueryKnowledgeBaseAction = do
-        q        <- param @Text "q"
-        mHubStr  <- paramOrNothing @Text "hubId"
+        let q       = param @Text "q"
+            mHubStr = paramOrNothing @Text "hubId"
         hubs     <- query @Hub |> fetch
         entries  <- case mHubStr of
             Nothing ->