feat(WP-0013): IHF Phase 12 — Platform Memory and Continuous Learning

Closes the long-range feedback loop: outcome signals now enrich the full
traceability chain and feed back into routing, triage, and AI proposals.

Schema (T01):
- outcome_correlations (CHECK correlation_type)
- pattern_performance_records
- adaptive_threshold_configs
- institutional_knowledge_entries (GIN tsvector FTS)
- learning_insights (CHECK insight_type)
- ALTER TABLE decision_records + requirement_candidates: outcome_summary JSONB
- AFTER INSERT trigger trg_enrich_lineage on outcome_signals
- contracts/core/ updated (outcome-summary-columns-v1, append-only addendum)

Correlation engine (T02):
- Application/Helper/CorrelationEngine.hs: pure annotation→outcome SQL
- Web/Controller/OutcomeCorrelations.hs: ComputeCorrelationsAction + index

Pattern performance (T03):
- Web/Controller/PatternPerformance.hs: ComputePatternPerformanceAction

Adaptive thresholds (T04):
- Web/Controller/AdaptiveThresholds.hs: CalibrateThresholdsAction
- Application/Helper/FrictionScore.hs: applyAdaptiveWeights

Institutional knowledge (T05):
- DistilDecisionAction in DecisionRecords controller
- Web/Controller/InstitutionalKnowledge.hs: QueryKnowledgeBaseAction

Lineage enrichment (T06):
- Web/Controller/LineageEnrichment.hs: EnrichLineageAction (batch backfill)
- enrich_lineage_on_outcome_batch() PL/pgSQL helper in migration

Learning dashboard (T07):
- Web/Controller/LearningDashboard.hs: 5-panel autoRefresh view
- "Learning" nav link in FrontController

API v2 learning endpoints (T08):
- GET /api/v2/outcome-correlations, /pattern-performance, /knowledge-base/{id}
- OpenAPI schemas: OutcomeCorrelation, PatternPerformanceRecord, InstitutionalKnowledgeEntry

GAAF scorecard + docs (T09):
- Core 3.8→3.9, Functional 3.6→3.8, overall 3.61→3.68
- CLAUDE.md: IHF v0.2 complete, no active workplan

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

contracts/core/append-only-events-v1.md

@@ -96,9 +96,26 @@ append semantics are enforced by application-layer controller conventions.
 
 ---
 
+## Phase 12 Addendum — Lineage Enrichment Trigger
+
+**Added in Phase 12 (IHUB-WP-0013 T06):** `outcome_signals` now has an
+`AFTER INSERT` trigger `trg_enrich_lineage` that calls
+`enrich_lineage_on_outcome()`.
+
+This trigger:
+- Is **AFTER INSERT only** — it never fires on UPDATE or DELETE.
+- Does **not modify `outcome_signals`** — it only enriches upstream records
+  (`decision_records.outcome_summary`, `requirement_candidates.outcome_summary`).
+- Is consistent with the append-only invariant: the `outcome_signals` row
+  itself remains immutable after insertion.
+
+---
+
 ## Implementation Reference
 
 - Functions: `prevent_interaction_event_mutation()`,
   `prevent_outcome_signal_mutation()` in `Application/Schema.sql`
+- Phase 12: `enrich_lineage_on_outcome()` — AFTER INSERT trigger on
+  `outcome_signals`; enriches non-append-only columns on upstream tables only
 - The architectural fitness function `Test/Architecture/LayerBoundarySpec.hs`
   (Test 1) verifies these trigger names are present in the schema