docs(releases): curate the v16 release page — backend + Console coverage for 16.0.0 (#3322)

Adds content/docs/releases/v16.mdx (the check:release-notes drift guard requires a curated page per released spec major; spec is at 16.0.0-rc.0), wires it into meta.json, and updates the index. Sourced from the deduped 16.0.0-rc.0 changesets, changeset-less approvals/capability commits, and the bundled objectui 15.0.0→16.0.0 range.

Author: os-zhuang

content/docs/releases/index.mdx

@@ -18,7 +18,8 @@ migration steps, then covers new capabilities and notable fixes.
 
 ## Versions
 
-- [v15.0.0](/docs/releases/v15) — Explain record access layer by layer, a docked AI workspace in the Console, project-ready Gantt charts, and phone sign-in; 15.1 adds permission-following attachments, no-code third-party connectors, dashboard-wide filters, pinyin search, and whole-record inline editing — with materially safer multi-tenant and write-path defaults (current series: 15.1.0).
+- [v16.0.0](/docs/releases/v16) — One org identifier (`organizationId`) across hooks and actions, quorum + per-group sign-off (会签) approvals with metadata-declared decision actions, time-relative automations, filtered roll-ups, strict dashboard widgets, an identity-scoped MCP stdio transport, and a platform-wide enforce-or-remove sweep that makes dead metadata loud (current series: 16.0.0-rc.0).
+- [v15.0.0](/docs/releases/v15) — Explain record access layer by layer, a docked AI workspace in the Console, project-ready Gantt charts, and phone sign-in; 15.1 adds permission-following attachments, no-code third-party connectors, dashboard-wide filters, pinyin search, and whole-record inline editing — with materially safer multi-tenant and write-path defaults (final release: 15.1.1).
 - [v14.0.0](/docs/releases/v14) — ADR-0090 vocabulary convergence completed, object `enable.*` flags become real gates, admin user management, phone/SMS auth, book-audience enforcement, data-lifecycle contract, and effective-dated grants (final release: 14.8.0).
 - [v13.0.0](/docs/releases/v13) — Permission Model v2 (ADR-0090): Roles and Profiles converge on Positions, custom objects default to private, plus an explain engine, delegated administration, and self-serve MCP OAuth.
 - [v12.0.0](/docs/releases/v12) — Anonymous data access denied by default (ADR-0056 D2), adaptive record surfaces, an enforced protocol-version handshake, and build-gating author-time lints.

content/docs/releases/meta.json

@@ -1,5 +1,5 @@
 {
   "title": "Releases",
   "icon": "Tag",
-  "pages": ["index", "v15", "v14", "v13", "v12", "v9", "implementation-status"]
+  "pages": ["index", "v16", "v15", "v14", "v13", "v12", "v9", "implementation-status"]
 }