feat(WP-0009): IHF GAAF Compliance Foundation — type registries, extension manifests, architectural contracts

Implements IHUB-WP-0009: closes four GAAF-2026 gaps before domain hub work begins.
- TypeRegistry helper + controllers/views (hub_kind, hub_capability_manifest)
- HubCapabilityManifest entity with validation and registry linkage
- ARCHITECTURE-LAYERS.md + CI-enforced boundary contracts
- Alembic migration 1743724800, fitness tests (Test/Architecture/)
- GAAF spec, Operational Architecture spec, domain hub extension guide
- Updates to CLAUDE.md, SCOPE.md, Schema.sql, Routes, FrontController, Types

state_hub_sync: pending (tunnel was STALE at completion time; run fix-consistency)

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

contracts/README.md

@@ -0,0 +1,78 @@
+# IHF Contract Catalog
+
+**Framework:** GAAF-2026
+**Last reviewed:** 2026-03-31
+**Repository:** inter-hub
+
+This directory contains the versioned, machine-readable contracts for each
+GAAF-2026 layer. Contract files are the authoritative declaration of
+interface, invariants, compatibility rules, and validation requirements for
+every public surface in the framework.
+
+The canonical implementation of each contract is the PostgreSQL schema and
+Haskell controllers. These files are the *discoverable declaration* — the
+human and agent-readable companion that makes intent explicit without
+requiring the source code to be read.
+
+---
+
+## Core Contracts
+
+| Contract | File | Version | Status |
+|---|---|---|---|
+| Widget Envelope | [core/widget-envelope-v1.md](core/widget-envelope-v1.md) | 1.0 | Active |
+| Append-Only Events | [core/append-only-events-v1.md](core/append-only-events-v1.md) | 1.0 | Active |
+
+Core contracts are **immutable after activation**. New requirements produce a
+new version (v1.1, v2.0); the old version remains readable for audit.
+
+---
+
+## Functional Contracts
+
+| Contract | File | Version | Status |
+|---|---|---|---|
+| Interaction Reporting API | [functional/interaction-reporting-v1.md](functional/interaction-reporting-v1.md) | 1.0 | Active |
+| Module Maturity Labels | [functional/module-maturity-labels.md](functional/module-maturity-labels.md) | 1.0 | Active |
+
+Functional contracts are **evolvable with minor-version notice**. Breaking
+changes require a major version bump and a deprecation window.
+
+---
+
+## Extensions Contracts
+
+| Contract | File | Version | Status |
+|---|---|---|---|
+| Hub Capability Manifest | [extensions/hub-capability-manifest-v1.md](extensions/hub-capability-manifest-v1.md) | 1.0 | Active |
+
+Extensions contracts govern how domain hubs register their vocabulary and
+capabilities with the framework.
+
+---
+
+## Contract Lifecycle
+
+```
+Draft → Active → Superseded
+              ↓
+           (never deleted — old versions remain for audit)
+```
+
+A contract becomes Active when:
+- Its corresponding schema and code are deployed
+- It is referenced in `ARCHITECTURE-LAYERS.md`
+
+A contract is Superseded when a new version replaces it. The old file
+remains with a `superseded_by` note at the top.
+
+---
+
+## Adding a New Contract
+
+1. Create the file in the appropriate layer directory
+2. Follow the header format: name, version, date, status, layer
+3. Document: interface, invariants, compatibility rules, validation rules,
+   failure mode
+4. Add an entry to this README table
+5. Reference it in `ARCHITECTURE-LAYERS.md`