feat: implement governed wiki vertical slice

docs/WIKI_DOMAIN_BOUNDARY.md

@@ -24,8 +24,37 @@ revision as evidence. Search indexes only revisions the principal may
 discover. Projects, Tickets, and Cases may link pages as living knowledge.
 Connectors owns MediaWiki/BlueSpice discovery, synchronization, and migration.
 
-## First Slice
+## Governed Vertical Slice
 
-Implement spaces, revisioned pages, links, access checks, and
-permission-aware search publication before adding rich editing or external
-synchronization.
+The native slice stores a current editorial projection plus an immutable page
+revision for every creation, edit, publication, redirect, or archive action.
+Writes require the expected revision and an idempotency key. A published page
+can gain a later draft without withdrawing its last published revision from
+readers or Search.
+
+Visibility is either tenant-wide or restricted to exact account, identity,
+membership, group, role, or function-assignment tokens. Pages inherit their
+space access by default and may define an explicit override. Permissions remain
+distinct for reading, editing, commenting, publishing, and space
+administration, and are checked again at each service action.
+
+Typed links retain the owner module and stable resource identity. Attachment
+links can target Files or DMS only; no binary bytes are copied into Wiki.
+External provenance can be recorded without claiming transport authority.
+
+Search receives only the last published revision, effective visibility, and
+ACL tokens, and rechecks every result against current Wiki state. Drafts and
+archives never become searchable documents. DSAR discovery matches exact
+subject identifiers in ACL membership, actor attribution, and the subject's
+own comments. Minimization remains a manual knowledge-owner and retention
+decision.
+
+## Current Limits
+
+- external MediaWiki or BlueSpice discovery, credentials, migration execution,
+  synchronization, and reconciliation require a Connectors provider
+- the initial editor stores governed plain text; rich-text editing and presence
+  awareness can be layered over the same revision contract later
+- a page with active child pages must have those children moved or archived
+  before its path changes or it is archived, preventing silent descendant path
+  drift