feat(P4): IHF Phase 4 complete — Outcome Observation and Antifragility Loop

Closes the IHF improvement loop. Full antifragility chain now traversable:
Widget → Annotation → Candidate → Requirement → Decision → Deployment → OutcomeSignal

New artifacts:
- DeploymentRecord (immutable, links DecisionRecord to a deployed version)
- OutcomeSignal (append-only; DB trigger prevents UPDATE/DELETE)
- ChangeEvaluation (one-per-deployment; UNIQUE constraint; 1–5 score)

New capabilities:
- DeploymentRecordsController (index, show, new, create)
- RecordOutcomeSignalAction — capture improved/regressed/neutral/inconclusive signals
- Pre/post comparison panel on deployment show (±30-day event/annotation counts)
- Regression detection — improved signal followed by high/critical annotation
- ChangeEvaluation — idempotent score+rationale per deployment
- Recurrence tracking — cycle count per widget, leaderboard
- AntifragilityDashboardAction (autoRefresh, 5 panels) per hub
- Phase 4 integration tests (T01–T08 logic coverage)
- docs/phase4-summary.md; SCOPE.md updated to Phase 4 complete

State Hub: workstream 07e9c860 → completed

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

Web/FrontController.hs

@@ -15,6 +15,7 @@ import Web.Controller.AnnotationThreads ()
 import Web.Controller.RequirementCandidates ()
 import Web.Controller.Requirements ()
 import Web.Controller.DecisionRecords ()
+import Web.Controller.DeploymentRecords ()
 import Web.Controller.Sessions ()
 
 instance FrontController WebApplication where
@@ -28,6 +29,7 @@ instance FrontController WebApplication where
         , parseRoute @RequirementCandidatesController
         , parseRoute @RequirementsController
         , parseRoute @DecisionRecordsController
+        , parseRoute @DeploymentRecordsController
         ]
 
 instance InitControllerContext WebApplication where
@@ -56,6 +58,7 @@ defaultLayout inner = [hsx|
                 <a href={RequirementCandidatesAction} class="text-sm text-gray-600 hover:text-gray-900">Candidates</a>
                 <a href={RequirementsAction} class="text-sm text-gray-600 hover:text-gray-900">Requirements</a>
                 <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>
                 <div class="ml-auto">
                     <a href={DeleteSessionAction} class="text-sm text-gray-500 hover:text-gray-700">Sign out</a>
                 </div>