fix: stop sticky jump-to-present bottom repins

[Just-Insane]

Description

Fixes #328

Keep the keyboard-close recovery from snapping readers back to live bottom after they have already scrolled away during the same keyboard session. The repin path now only fires when the session started at bottom and the timeline is still bottom-pinned at keyboard-dismiss time.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).
  The change tightens shouldRepinBottomAfterKeyboardClose so the keyboard-dismiss recovery only repins when the room both started the keyboard session at live bottom and is still at bottom when the viewport expands again. RoomTimeline now passes the current bottom state into that guard, which stops the close-animation path from dragging an off-bottom reader back to present after they intentionally scrolled upward. The keyboard-bottom recovery tests were updated to cover the new guard, and a patch changeset was added for the user-facing regression.

Validation

• pnpm lint
• pnpm fmt:check
• pnpm typecheck
• pnpm test:run
• pnpm knip
• pnpm build

[github-actions]

Sentry Preview Error Triage

No Sentry errors found for this PR's preview deployment as of Tue, 23 Jun 2026 15:14:09 GMT.

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[github-actions]

Deploying with    Cloudflare Workers

Status	Preview URL	Commit	Alias	Updated (UTC)
✅ Deployment successful!	https://pr-337-charm.justin-tech.workers.dev	d2b5595	pr-337	Tue, 23 Jun 2026 15:15:56 GMT

[github-code-quality]

Code Coverage Overview

Languages: JavaScript

JavaScript / code-coverage/vitest

The overall coverage remains at 27%, unchanged from the integration branch.

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Point the changeset at the Charm package

This repo's release config defines a single package from package.json (name: "charm") via [package] in knope.toml, and the documented single-package changeset form is default: patch; there is no configured charm-client package. With this frontmatter the release tooling will not apply this entry to the app's version/changelog, so this fix can be omitted from the release notes or break release preparation. Please target default or charm instead.

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