Register shard-wiki capabilities (7 wiki.* registry entries)

Adds capability.wiki.{shard-orchestration, adapter-contract, page-model,
coordination-journal, overlay, federation-models, engine-typed-extensions}
with honest D/A/C/R maturity vectors, relations, and shard-wiki spec/test
evidence; updates registry/indexes/capabilities.yaml. reuse-surface validate: ok.
Source: shard-wiki SHARD-WP-0013 T1.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

registry/indexes/capabilities.yaml

@@ -133,4 +133,80 @@ capabilities:
     owner: state-hub
     path: registry/capabilities/capability.statehub.workstream-coordinate.md
     tags: [state-hub, coordination, workplans]
-    consumption_modes: [service API, HTTP REST]
+    consumption_modes: [service API, HTTP REST]
+  - 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: D2 / 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]