docs(release): align 2026.921.0-beta.1 stable notes header with v2026.1001.0 (#14882)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Releases are published by `release.yml`. A stable release promotes a
soaked beta, and the stable notes live on master in
`releases/beta/v<beta>.md` until the promotion runs.
> - The curated notes for `2026.921.0-beta.1` have the title `Paperclip
v2026.924.0` and the date `2026-09-24`. That stable did not ship. No
`v2026.924.0` tag or release exists.
> - The next promotion of this beta uses `stable_date=2026-10-01`.
`scripts/release.sh stable --print-version --date 2026-10-01` resolves
to `2026.1001.0`.
> - `publish_stable` reads this file verbatim and uses it as the GitHub
Release body. `canonicalize_stable_notes` copies it to
`releases/v2026.1001.0.md`. Nothing rewrites the header.
> - This pull request updates the title, the release date, and the intro
sentence to `v2026.1001.0` and `2026-10-01`.
> - The benefit is a GitHub Release page and a canonical notes file that
show the correct version and date.

## Linked Issues or Issue Description

**Describe the documentation problem**

The stable notes file `releases/beta/v2026.921.0-beta.1.md` names a
stable version and release date that do not match the version the
release workflow will publish.

**Where is the problem**

`releases/beta/v2026.921.0-beta.1.md`, lines 1, 3, and 5.

**Proposed fix**

Change `v2026.924.0` to `v2026.1001.0` and `2026-09-24` to `2026-10-01`
in the three places that name the version or date. Change nothing else
in the file.

## What Changed

- Title: `# Paperclip v2026.924.0` → `# Paperclip v2026.1001.0`
- Release date: `> Released: 2026-09-24` → `> Released: 2026-10-01`
- Intro sentence: `Paperclip v2026.924.0 carries 77 commits` →
`Paperclip v2026.1001.0 carries 77 commits`

## Verification

- `git diff master --stat` shows one file with 3 insertions and 3
deletions.
- `grep -n '924' releases/beta/v2026.921.0-beta.1.md` returns no lines.
- `git show master:scripts/release.sh > /tmp/r.sh && bash /tmp/r.sh
stable --print-version --date 2026-10-01` prints `2026.1001.0`.
- The rest of the file is byte-identical to master.

## Risks

- Low risk. This is a documentation-only change to a release notes file.
No code or workflow changes.
- If the stable promotion is dispatched with a different `stable_date`,
the header must be updated again to match.

## Model Used

- Claude Fable 5.1 (model ID `claude-fable-5-1`), run as a Paperclip
agent through the Claude Agent SDK, with tool use (shell, git, GitHub
CLI). No extended thinking mode was configured beyond the default.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [ ] I have added or updated tests where applicable (not applicable:
documentation-only change)
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

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

Co-authored-by: Bender (Fable) <noreply@paperclip.ing>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

releases/beta/v2026.921.0-beta.1.md

@@ -1,8 +1,8 @@
-# Paperclip v2026.924.0
+# Paperclip v2026.1001.0
 
-> Released: 2026-09-24
+> Released: 2026-10-01
 
-Paperclip v2026.924.0 carries 77 commits, promoted from `2026.921.0-beta.1`. The headline is reliability: a deep hardening pass over the native runner and chat recovery — approval and Stop races, session continuity, sandbox reconnection and cleanup — alongside a friendlier face: agent personas throughout the app, an animated onboarding character, and a rebuilt Slack setup. Around those: agents can review GitHub pull requests as scheduled review bots, Railway joins the connector catalog with governed deployment tools, approvals and answers queue during active runs instead of bouncing, and execution harnesses now default to full auto.
+Paperclip v2026.1001.0 carries 77 commits, promoted from `2026.921.0-beta.1`. The headline is reliability: a deep hardening pass over the native runner and chat recovery — approval and Stop races, session continuity, sandbox reconnection and cleanup — alongside a friendlier face: agent personas throughout the app, an animated onboarding character, and a rebuilt Slack setup. Around those: agents can review GitHub pull requests as scheduled review bots, Railway joins the connector catalog with governed deployment tools, approvals and answers queue during active runs instead of bouncing, and execution harnesses now default to full auto.
 
 ## Breaking Changes