docs(upgrading): add the v18.2.0 row to the per-release table (#26830)

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_Requested by **Warren** · [project
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Fixes #26631

Clause-②: no
Metadata-protocol: none

## 维护者速读

- **改了什么:** 升级指南 `upgrading.mdx` 的「每个版本的升级说明在哪」表格加了一行 v18.2.0,指向 18.2.0
发布页的升级清单。
- **为什么改:** 18.2.0 已发布且发布页带升级清单,但这张表停在 v18.1.0,从 18.1 往上升的用户在指南里找不到 18.2
的入口。
- **风险与回滚:** 纯文档一行,无运行时改动,不发包;回滚 = revert 本 PR。
- **先看:** `content/docs/upgrading.mdx` 「Per-release specifics」表的第一行。
- **两分钟验证:** 打开 `/docs/upgrading`,点表中 v18.2.0 一行的链接,应落到 18.2.0
发布页的「Upgrade checklist」小节。
- **需要你做的:** 无,席位落地。

## What changes

One row added to the per-release table in `content/docs/upgrading.mdx`,
above the v18.1.0 row:

```
| v18.2.0 | [Upgrade checklist — 18.2.0](/docs/releases/v18/18-2#upgrade-checklist) |
```

## Why

The table stopped at v18.1.0, while `content/docs/releases/v18/18-2.mdx`
(#26494) ships `## Upgrade checklist` (line 910), so the anchor is
`#upgrade-checklist`.

Nothing else moves with it: no other list in `upgrading.mdx` stops at
18.1, and no test or script pins the table's rows (searched `scripts/`,
`packages/`, `.github/`). `content/docs/releases/**` and `references/**`
are untouched. `content/docs/**` publishes no package, hence
`skip-changeset`.

## Verification

`node scripts/pm/dispatch-gates.mjs --commands` derived 44 gate families
for this diff; all 44 exit 0, and `--ran` reconciles 44 derived / 44 run
/ 0 NOT-MEASURED. That includes `check:doc-anchors`,
`check:docs-redirects`, `check:corpus-claim-drift` and
`check:docs-transcript-drift` (the last after building
`@objectstack/lint`). Prerequisite builds before the first exit 0:
`@objectstack/lint...`, `@objectstack/formula`, `@objectstack/spec`,
`@objectstack/client(-react)...`.

## Human Minimum

- [x] 1. Schemas start as Zod; `packages/spec` holds no runtime logic.
(not touched)
- [x] 2. Every name I added uses the casing for its kind. (no names)
- [x] 3. No formatter ran; `pnpm lint` passes. (one mdx row, outside
ESLint's globs; not run locally)
- [x] 4. One issue, one branch off an up-to-date `main`, one pull
request.
- [x] 5. A change that publishes carries a changeset, and both
declaration lines are filled in here and in the changeset. (publishes
nothing)
- [x] 6. `packages/spec` touched: its generated artifacts are
regenerated and committed. (not touched)
- [x] 7. No hand edits to `content/docs/references/`,
`packages/*/CHANGELOG.md` or `content/docs/releases/`.
- [x] 8. Title, body and comments are in English. (except the 维护者速读
channel)
- [x] The *Before Submitting* list in CONTRIBUTING.md is done.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01JQwxbWQbmPGoJDwc2QWoUJ

Co-authored-by: Claude <noreply@anthropic.com>

Author: objectstack-fleet[bot]

content/docs/upgrading.mdx

@@ -463,6 +463,7 @@ the protocol-18 step, which `os migrate meta --from 17` lists for your sources
 
 | Release | Where its upgrade notes live |
 | :--- | :--- |
+| v18.2.0 | [Upgrade checklist — 18.2.0](/docs/releases/v18/18-2#upgrade-checklist) |
 | v18.1.0 | [Upgrade checklist — 18.1.0](/docs/releases/v18/18-1#upgrade-checklist) |
 | v18.0.0 | [Upgrade checklist — 18.0.0](/docs/releases/v18/18-0#upgrade-checklist) · [Upgrading to 18.0](#upgrading-to-180) (the ownership ceremony) · [v18](/docs/releases/v18) |
 | v17.7.0 | [Upgrade checklist — 17.7.0](/docs/releases/v17/17-7#upgrade-checklist) |