docs: delete eight obsolete planning docs and point the root docs at the live pages

Ruling A on the obsolete-docs decision card. Deleted, history kept in git:
docs/NEXT_STEP.md, docs/DX_ROADMAP.md, docs/PLUGIN_ECOSYSTEM_MAP.md,
docs/upgrading-to-11.md, docs/v17-docs-sweep.md, docs/launch-readiness.md,
docs/plans/m1-project-artifact-schema.md and
docs/plans/release-15.1-test-plan.md.

- ARCHITECTURE.md becomes a pointer to the published architecture page.
- Root CHANGELOG.md keeps its history and gains a top line pointing at
  content/docs/releases/; its three links to the 11.x upgrade guide now
  resolve at commit df8aac4.
- RELEASE_NOTES.md is marked frozen, loses the "(in progress)" marker and the
  reference to a changeset file that never existed.
- docs/audits/README.md states the open -> closed -> archive/ lifecycle.
- Inbound references are rewritten: the published client-sdk page, the
  platform-checklist README, packages/metadata/ROADMAP.md and
  PLATFORM_GAPS_FROM_TEMPLATES.md; source comments that cited a deleted
  file now name the commit that holds it.
- check-required-contexts drops docs/launch-readiness.md from its scan set
  (it hard-fails on a surface it cannot read); check-doc-authoring's
  example guide name is updated.

Claude-Session: https://claude.ai/code/session_01SQ8bET7S4BDrvJdXyuLdYi
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

ARCHITECTURE.md

@@ -1,5 +1,8 @@
 # Changelog
 
+> **Current release notes live in [`content/docs/releases/`](content/docs/releases).** This file
+> keeps the historical entries below and is no longer extended.
+
 All notable changes to the ObjectStack Protocol will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
@@ -1593,7 +1596,7 @@ Followup to M10.30a. Walked every Setup menu in a real tenant; produced verdict
 > deprecations/retirements, and additions to the authorable surface — so this file again
 > does what its header promises. Releases `4.0.2`–`9.11.0` remain documented in the
 > per-package changelogs. For every `10.x → 11.x` migration step see
-> [docs/upgrading-to-11.md](./docs/upgrading-to-11.md); the compatibility gates that
+> [docs/upgrading-to-11.md](https://github.com/objectstack-ai/objectstack/blob/df8aac41f2d9d14db04afdfe48511216419dafc0/docs/upgrading-to-11.md); the compatibility gates that
 > govern what may break and when are ADR-0059, and the upgrade-communication contract is
 > ADR-0087.
 
@@ -1706,7 +1709,7 @@ never as per-surface hint blocks (#2521).
 ## [11.1.0] — 2026-06-28
 
 Completes the 11.0 breaking line (see
-[docs/upgrading-to-11.md](./docs/upgrading-to-11.md)).
+[docs/upgrading-to-11.md](https://github.com/objectstack-ai/objectstack/blob/df8aac41f2d9d14db04afdfe48511216419dafc0/docs/upgrading-to-11.md)).
 
 ### Removed
 - **`DriverInterface` type alias** (deprecated in 11.0) — use `IDataDriver` (same
@@ -1726,7 +1729,7 @@ Completes the 11.0 breaking line (see
 ## [11.0.0] — 2026-06-27
 
 **Major.** Every breaking change of the 11 line, each with a concrete migration, is in
-[docs/upgrading-to-11.md](./docs/upgrading-to-11.md) (also covering the package-level
+[docs/upgrading-to-11.md](https://github.com/objectstack-ai/objectstack/blob/df8aac41f2d9d14db04afdfe48511216419dafc0/docs/upgrading-to-11.md) (also covering the package-level
 breaks outside the spec surface: Hono-only HTTP adapters, `client-react` canonical query
 fields, `OS_*` env renames).
 

CHANGELOG.md

@@ -1,17 +1,17 @@
 # Release Notes
 
-> **📓 This file is historical.** Current, developer-facing release notes live in
+> **📓 This file is historical and frozen — nothing new is added to it.** Current, developer-facing release notes live in
 > the curated per-major pages under [`content/docs/releases/`](content/docs/releases)
 > — they lead with breaking changes + migration and cover backend **and** Console
 > (frontend) per platform version. For exhaustive per-package detail, see each
 > package's changeset-generated `CHANGELOG.md`. The entries below are kept for
 > historical reference; see `docs/releases-maintenance.md` for how release history
 > is maintained.
 
-> **v5.0 (2026): `project` → `environment`.** The runtime concept formerly called *Project* (per-tenant business workspace; Org/Project/Branch hierarchy) is now called *Environment* throughout the codebase: CLI flags (`--environment`/`-e`), HTTP paths (`/api/v1/environments/:environmentId/...`), headers (`X-Environment-Id`), env vars (`OS_ENVIRONMENT_ID`), exported symbols (`createSystemEnvironmentPlugin`, `SYSTEM_ENVIRONMENT_ID`), DB columns (`environment_id`), and JSON schemas (`EnvironmentArtifact`) all use the new term with no aliases or deprecation shims. The word "project" elsewhere in this document still refers to the npm/monorepo sense (i.e., the framework as a software project). See `.changeset/v5-project-to-environment-rename.md` for the full breaking-change list and ADR-0006 for the rationale.
+> **v5.0 (2026): `project` → `environment`.** The runtime concept formerly called *Project* (per-tenant business workspace; Org/Project/Branch hierarchy) is now called *Environment* throughout the codebase: CLI flags (`--environment`/`-e`), HTTP paths (`/api/v1/environments/:environmentId/...`), headers (`X-Environment-Id`), env vars (`OS_ENVIRONMENT_ID`), exported symbols (`createSystemEnvironmentPlugin`, `SYSTEM_ENVIRONMENT_ID`), DB columns (`environment_id`), and JSON schemas (`EnvironmentArtifact`) all use the new term with no aliases or deprecation shims. The word "project" elsewhere in this document still refers to the npm/monorepo sense (i.e., the framework as a software project). See ADR-0006 for the rationale.
 
 
-## v4.0.4 — Release Readiness: Documentation Alignment _(in progress)_
+## v4.0.4 — Release Readiness: Documentation Alignment
 
 ### 🎯 Purpose
 

RELEASE_NOTES.md

@@ -577,7 +577,7 @@ The `find` method accepts an options object with **canonical** (recommended) fie
 | `expand` | `Record<string, any>` or `string[]` | Relation loading (JOIN) | `{ owner: {} }` |
 
 <Callout type="info">
-**Canonical names recommended:** `find()` accepts the canonical names above; the legacy aliases (`select`, `filter`/`filters`, `sort`, `top`, `skip`) still work for backward compatibility, but new code should use the canonical names. (`@objectstack/client-react`'s `useQuery`/`useInfiniteQuery` hooks are stricter — the legacy aliases were removed there in v11; see `docs/upgrading-to-11.md`.)
+**Canonical names recommended:** `find()` accepts the canonical names above; the legacy aliases (`select`, `filter`/`filters`, `sort`, `top`, `skip`) still work for backward compatibility, but new code should use the canonical names. (`@objectstack/client-react`'s `useQuery`/`useInfiniteQuery` hooks are stricter — the legacy aliases were removed there in v11.)
 </Callout>
 
 ### Batch Options