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/ApiRateLimit.hs

@@ -21,11 +21,10 @@ checkRateLimitAndLog ::
     , ?request :: Request
     ) =>
     ApiConsumer ->
-    Text ->   -- endpoint path
     Text ->   -- HTTP method
-    Int  ->   -- response status code (0 if not yet known; log after)
+    Text ->   -- endpoint path
     IO ()
-checkRateLimitAndLog consumer endpoint method _statusCode = do
+checkRateLimitAndLog consumer endpoint method = do
     -- Check rate limit: requests in last 60 seconds
     rows1 <- sqlQuery
         "SELECT COUNT(*) FROM api_request_log \