feat(P6/T01): Phase 6 schema — WidgetAdapterSpec, contracts, widgets.adapter_spec_id

Adds Phase 6 tables: envelope_emission_contracts, interaction_reporting_contracts,
widget_adapter_specs. Adds adapter_spec_id FK to widgets and api_key to hubs.
Seeds v1.0 contracts in migration. Registers Phase 6 controller types and routes.

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

Web/FrontController.hs

@@ -17,6 +17,9 @@ import Web.Controller.Requirements ()
 import Web.Controller.DecisionRecords ()
 import Web.Controller.DeploymentRecords ()
 import Web.Controller.AgentProposals ()
+import Web.Controller.EnvelopeEmissionContracts ()
+import Web.Controller.InteractionReportingContracts ()
+import Web.Controller.WidgetAdapterSpecs ()
 import Web.Controller.Sessions ()
 
 instance FrontController WebApplication where
@@ -32,6 +35,9 @@ instance FrontController WebApplication where
         , parseRoute @DecisionRecordsController
         , parseRoute @DeploymentRecordsController
         , parseRoute @AgentProposalsController
+        , parseRoute @EnvelopeEmissionContractsController
+        , parseRoute @InteractionReportingContractsController
+        , parseRoute @WidgetAdapterSpecsController
         ]
 
 instance InitControllerContext WebApplication where
@@ -62,6 +68,7 @@ defaultLayout inner = [hsx|
                 <a href={DecisionRecordsAction} class="text-sm text-gray-600 hover:text-gray-900">Decisions</a>
                 <a href={DeploymentRecordsAction} class="text-sm text-gray-600 hover:text-gray-900">Deployments</a>
                 <a href={AgentProposalsAction} class="text-sm text-gray-600 hover:text-gray-900">Agent</a>
+                <a href={WidgetAdapterSpecsAction} class="text-sm text-gray-600 hover:text-gray-900">Adapters</a>
                 <div class="ml-auto">
                     <a href={DeleteSessionAction} class="text-sm text-gray-500 hover:text-gray-700">Sign out</a>
                 </div>