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/CrossHubPropagation.hs

@@ -69,14 +69,16 @@ detectPropagations hubs annotations widgets frictionScores = do
             guard (not (any (\p -> p.patternType == "widget_type_friction" && p.summary == summary) existing))
             pure (srcHub, hubsWithHighFriction, "widget_type_friction", summary)
 
-    let allPatterns = clusterPropagations <> frictionPropagations
+    let allPatterns :: [(Id' "hubs", [Id' "hubs"], Text, Text)]
+        allPatterns = clusterPropagations <> frictionPropagations
 
-    mapM (\(srcHubId, affectedHubIds, ptype, summary) ->
-        newRecord @CrossHubPropagation
-            |> set #patternType    ptype
-            |> set #sourceHubId   (Just srcHubId)
-            |> set #affectedHubIds (toJSON (map show affectedHubIds))
-            |> set #summary        summary
-            |> set #status         "open"
-            |> createRecord
-        ) allPatterns
+    let insertPropagation (rawSrcId, affectedHubIds, ptype, summary) = do
+            let srcId = rawSrcId :: Id' "hubs"
+            newRecord @CrossHubPropagation
+                |> set #patternType    ptype
+                |> set #sourceHubId   (Just srcId)
+                |> set #affectedHubIds (toJSON (map show affectedHubIds))
+                |> set #summary        summary
+                |> set #status         "open"
+                |> createRecord
+    mapM insertPropagation allPatterns