[Web] Session Fork/Revert UI actions still missing in v1.3.15 despite issue #9661 being closed #21119

Description

Bug Description

I am running the latest v1.3.15 (released April 4, 2026) on a Linux VPS with opencode web.
The Fork and Revert actions for messages are completely missing from the UI in the Web interface.

I noticed that Issue #9661 was previously closed, but this version still does not display the UI buttons.

Steps to Reproduce

1. Run opencode web on v1.3.15.
2. Open the Web interface in a browser.
3. Start or open a session.
4. Hover over a user message (or right-click).
5. Result: No "Fork" or "Revert" action appears in the context menu or hover overlay.

Investigation Results (Code Level Analysis)

I have audited the running web frontend bundle and found that:

1. The Backend API is accessible: POST /session/{sessionID}/fork works correctly when triggered manually via the browser console.
2. The Frontend Logic exists: The web bundle contains the handler for /session/{sessionID}/fork.
3. The Translations exist: The key ui.message.forkMessage is present in the bundle.

Conclusion

The functionality and API are fully implemented and working, but the UI component responsible for rendering the action buttons in the Web client is likely failing to mount or being hidden by a CSS/logic condition in v1.3.15.

Environment

• OS: Linux (Ubuntu 20.04 aarch64)
• Opencode Version: v1.3.15
• Interface: Web (Running opencode web with Caddy reverse proxy)

Suggested Action

Since #9661 was closed but the button is still absent in v1.3.15, it seems the fix was either merged but not included in the release, or the fix is conditionally failing in the specific Web build. Please verify if the UI fix is intended to be present in v1.3.15.

Plugins

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OpenCode version

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Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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