[Existing app][Changelog Panel] Polish existing interaction states and copy

[kryputh]

Summary

Improve the existing Changelog Panel surface. This issue is intentionally scoped to existing app code and should not introduce a new standalone tool or unrelated feature.

Current area

changelog entries, panel visibility, read state, release grouping, and user-facing change summaries

Relevant paths

• src/features/changelog/ChangelogPanel.tsx
• src/features/changelog/useChangelog.ts
• src/features/changelog/data.ts

Goal

make the existing changelog panel useful for release comprehension and contributor handoff.

Work focus

Tighten the existing visual and interaction states: default, hover, focus, active, disabled, loading, empty, and error. Keep the current product behavior, but make the surface feel intentional and consistent with the Stealth Mail visual system.

Acceptance criteria

• Existing behavior remains intact; this is polish, not a new module.
• Primary and secondary actions have clear labels, disabled states, loading states, and empty states where applicable.
• The surface uses existing tokens/components before introducing new styling.
• Screenshots or a short before/after note are included in the PR.

Scope guardrails

• Keep the work inside the relevant existing app/module paths above unless a small shared helper is clearly justified.
• Do not add a new V1/V2 tool folder for this issue.
• Do not use real user data, secrets, private keys, or live customer mail.
• Keep copy and UI aligned with the Stealth Mail safety, speed, and sender-control positioning.

Suggested validation

• Run the most relevant unit or e2e tests for the touched area.
• Run �un x tsc --noEmit and �un run lint when the local environment supports the project dependency install.

[gloskull]

Hello, I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.

[Songu3020]

Hello, I’m a full stack developer with hands-on experience building with variety of tools including Nextjs, nodejs, nestjs, React, Typescript and more

I focus on writing clear, maintainable code and making sure features work as expected end to end, not just in isolation. I communicate progress regularly and keep things transparent as I work. I’m confident I can complete this task within an ETA of 4 HOURS

[grantfox-oss]

🦊 GrantFox — @Songu3020 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #996)
2. Your PR will be reviewed by the Stellar-Mail maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Songu3020's PR #1165 was approved and merged by @kryputh.

🏆 @Songu3020: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (48 total points). Track your full progress on GrantFox.

👏 Great work, @Songu3020! Keep contributing to Stellar-Mail.