Add capability registry scaffold and seed entries from reuse-surface

Bootstrap registry/indexes/capabilities.yaml and migrate helix_forge
capability entries owned by this repository for federation publishing.

registry/indexes/capabilities.yaml

@@ -0,0 +1,145 @@
+version: 1
+updated: '2026-06-16'
+domain: helix_forge
+capabilities:
+- id: capability.wiki.shard-orchestration
+  name: Wiki Shard Orchestration
+  summary: Present a union of pages across heterogeneous wiki-shaped shards while
+    preserving each shard's provenance, capabilities, and history.
+  vector: D5 / A2 / C2 / R1
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.shard-orchestration.md
+  tags:
+  - wiki
+  - federation
+  - orchestration
+  - union
+  - shard-wiki
+  consumption_modes:
+  - source module
+- id: capability.wiki.adapter-contract
+  name: Capability-Aware Shard Adapter Contract
+  summary: A versioned backend interface where each binding declares a verified capability
+    profile, so federation ops degrade by capability.
+  vector: D5 / A2 / C2 / R1
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.adapter-contract.md
+  tags:
+  - wiki
+  - adapter
+  - capability
+  - contract
+  - conformance
+  - shard-wiki
+  consumption_modes:
+  - source module
+- id: capability.wiki.page-model
+  name: Backend-Neutral Wiki Page Model
+  summary: A Markdown-first but stretchable page model with stable identity separate
+    from placement and layered provenance.
+  vector: D5 / A2 / C2 / R1
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.page-model.md
+  tags:
+  - wiki
+  - page-model
+  - identity
+  - provenance
+  - markdown
+  - shard-wiki
+  consumption_modes:
+  - source module
+- id: capability.wiki.coordination-journal
+  name: Event-Sourced Coordination Journal
+  summary: An append-only, totally-ordered-per-space decision log whose current state
+    is a derived fold; git-addressable history.
+  vector: D5 / A2 / C2 / R1
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.coordination-journal.md
+  tags:
+  - wiki
+  - event-sourcing
+  - coordination
+  - git
+  - journal
+  - shard-wiki
+  consumption_modes:
+  - source module
+- id: capability.wiki.overlay
+  name: Overlay-Before-Mutation Write Path
+  summary: Non-destructive edits (draft -> patch -> apply-under-drift) that let read-only
+    or limited backends be edited safely without silent remote mutation.
+  vector: D5 / A2 / C2 / R1
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.overlay.md
+  tags:
+  - wiki
+  - overlay
+  - patch
+  - write-path
+  - conflict
+  - shard-wiki
+  consumption_modes:
+  - source module
+- id: capability.wiki.federation-models
+  name: Selectable Federation-Model Taxonomy
+  summary: Federation as a plural, composable coordination axis (fork+journal, VCS-replication,
+    query-join, feed, activity-streams, engine-mirror) selected per space.
+  vector: D4 / A0 / C1 / R0
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.federation-models.md
+  tags:
+  - wiki
+  - federation
+  - taxonomy
+  - composable
+  - shard-wiki
+  consumption_modes:
+  - informational
+- id: capability.wiki.engine-typed-extensions
+  name: Wiki Engine with Typed Extensions
+  summary: A small-core wiki engine realizing a typed-extension framework that addresses
+    all wiki use cases and lets each shard activate only the features it needs.
+  vector: D3 / A0 / C0 / R0
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.engine-typed-extensions.md
+  tags:
+  - wiki
+  - engine
+  - typed-extensions
+  - feature-activation
+  - shard-wiki
+  consumption_modes:
+  - informational
+- id: capability.wiki.derived-views
+  name: Wiki Derived Views
+  summary: Recomputable views over a wiki union — BackLinks, RecentChanges, AllPages,
+    SiteMap, and (delegate-or-derive) Search — carrying provenance.
+  vector: D3 / A0 / C0 / R0
+  domain: helix_forge
+  status: draft
+  owner: shard-wiki
+  path: registry/capabilities/capability.wiki.derived-views.md
+  tags:
+  - wiki
+  - derived-views
+  - backlinks
+  - recentchanges
+  - search
+  - shard-wiki
+  consumption_modes:
+  - informational