tui: cannot close tab for active conversation — tab reappears after clicking X

Summary

Cannot close the tab for the current active conversation in the TUI. Clicking the X causes the tab to briefly disappear then reappear. Other tabs in the same project close normally. The tab persists across restarts.

Environment

• opencode version: 1.18.18
• OS: Darwin 27.0.0 (arm64, macOS)
• Terminal: ghostty (TERM=xterm-256color, COLORTERM=truecolor)
• Shell: /bin/zsh
• Install/channel: beta (0.0.0-beta-17639 also reported by skill runtime)
• Active plugins: env-protection.js, wakatime.js, kdco-primitives/index.ts, notify.ts, worktree.ts, opencode-see-image@1.3.2

Reproduction

1. Open a project with multiple chat tabs in the TUI.
2. Start or continue a conversation in one of the tabs (so it is the active session).
3. Click the X on that tab to close it.
4. Tab briefly disappears then reappears.
5. Restart opencode and reopen the project — the tab is still there and still cannot be closed.

Expected Behavior

Clicking the X on a tab should close it, same as every other tab in the project.

Actual Behavior

The tab briefly disappears then immediately reappears. This persists across restarts. Other tabs in the same project close normally — only the active conversation tab is affected.

Additional Context

• Reproducible consistently on this one tab.
• Other tabs (other conversations in the same project) close fine.
• No error messages or visual indicators beyond the reappear behavior.
• The version string from opencode --version reports 1.18.18; the skill runtime snapshot reports 0.0.0-beta-17639. Both are noted in case of version mismatch relevance.