fix: replay composer and emoji follow-up

[Just-Insane]

Description

Restore centered single-line composer alignment, add breathing room back to jumbo emoji-only message lines, and normalize the bookmarks sidebar icon to match the adjacent quick-tool icons.

Related to #343

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 AI-assisted portion restores single-line centering in src/app/components/editor/Editor.tsx, adds small vertical breathing room to jumbo emoji variants in src/app/components/message/layout/layout.css.ts, and switches the inbox bookmarks nav icon to BookmarkSimple via src/app/pages/client/inbox/Inbox.tsx and src/app/components/icons/phosphor.tsx so it matches the surrounding quick-tool icons.

[github-actions]

Sentry Preview Error Triage

No Sentry errors found for this PR's preview deployment as of Tue, 23 Jun 2026 20:41:13 GMT.

This comment updates automatically after each push.

[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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[github-actions]

Deploying with    Cloudflare Workers

Status	Preview URL	Commit	Alias	Updated (UTC)
✅ Deployment successful!	https://pr-347-charm.justin-tech.workers.dev	407dc2b	pr-347	Tue, 23 Jun 2026 20:44:07 GMT