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/core/widget-envelope-v1.md

@@ -0,0 +1,88 @@
+# Widget Envelope Contract
+
+**Name:** widget-envelope
+**Version:** 1.0
+**Date:** 2026-03-31
+**Status:** Active
+**Layer:** Core
+**Immutable:** Yes — changes require v1.1 with backwards-compatible additions only
+
+---
+
+## Purpose
+
+The Widget Envelope is the metadata boundary attached to every rendered widget.
+It enables the IHF capture pipeline to attribute any DOM event to a governed
+widget without coupling to the widget's implementation.
+
+Any UI technology that emits the required `data-*` attributes on a DOM element
+is a first-class IHF participant.
+
+---
+
+## Required Attributes
+
+Every widget root element **MUST** carry all of the following:
+
+| Attribute | Format | Example |
+|---|---|---|
+| `data-widget-id` | UUID (RFC 4122) | `data-widget-id="550e8400-e29b-41d4-a716-446655440000"` |
+| `data-hub-id` | Registered hub slug (TEXT) | `data-hub-id="ops-hub"` |
+| `data-view-context` | Dot-separated path (TEXT) | `data-view-context="ops.incidents.list"` |
+| `data-widget-type` | Registered name from `widget_type_registry` | `data-widget-type="chart"` |
+
+---
+
+## Optional Attributes
+
+| Attribute | Format | Notes |
+|---|---|---|
+| `data-capability-ref` | TEXT | Links widget to a hub capability |
+| `data-policy-scope` | Registered name from `policy_scope_registry` | Defaults to `internal` if absent |
+| `data-widget-version` | Integer as string | Current widget version number |
+| `data-experiment-variant` | TEXT | A/B experiment identifier |
+| `data-requirements-thread-ref` | UUID | Links to an open AnnotationThread |
+
+---
+
+## Validation Rules
+
+1. `data-widget-id` must be a valid UUID. Non-UUID values cause the envelope to
+   be treated as malformed.
+2. `data-hub-id` must match the `slug` of a registered hub in the `hubs` table.
+   Unknown hub slugs are logged but do not block event capture.
+3. `data-widget-type` must exist in `widget_type_registry` with `status = 'active'`
+   at the time of capture. Events from deprecated types are accepted but flagged.
+4. `data-view-context` has no format enforcement in v1.0 beyond non-empty.
+
+---
+
+## Failure Mode
+
+- **Missing required attribute**: the capture pipeline logs a
+  `malformed_envelope` event with the missing attribute names in `metadata`.
+  The original interaction event is **not** stored. This is fail-safe, not
+  fail-loud — the UI does not crash.
+- **Unknown hub slug**: event is stored with `metadata.hub_warning = "unknown_hub_slug"`.
+- **Unregistered widget_type**: event is stored with
+  `metadata.type_warning = "unregistered_widget_type"`. No 422 is returned to
+  the frontend (retroactive registration is possible).
+
+---
+
+## Backwards Compatibility Rule
+
+v1.0 is frozen. New optional attributes may be added in v1.1 without breaking
+existing implementations. Removing any attribute, or making an optional
+attribute required, requires a new major version (v2.0) with a migration window.
+
+---
+
+## Implementation Reference
+
+- Schema enforcement: `widgets.widget_type` validated against `widget_type_registry`
+  on create/update in `WidgetsController`
+- Client-side: `static/ihf-annotation-launcher.js` reads `data-widget-id` and
+  `data-hub-id` from the nearest ancestor with these attributes
+- Server-side envelope rendering: `widgetEnvelope` HSX helper in
+  `Application/Helper/View.hs`