feature: session favorites/pinning for quick access to important sessions #42940

Summary

Feature request: add the ability to favorite/pin/star sessions so users can quickly find important sessions later. Currently there's no way to mark a session as noteworthy — the session list supports search and order, but sessions with similar titles or aging timestamps are hard to relocate.

Environment

• opencode version: 0.0.0-beta-17498
• OS: Linux 6.12.95+deb13-amd64 (linux x64)
• Terminal: TERM_PROGRAM=WezTerm, TERM=xterm-256color, COLORTERM=truecolor
• Shell: /bin/bash
• Install/channel: beta

Current Behavior

The session API (GET /api/session) supports filtering by search, order, workspace, parentID, directory, project, subpath, and cursor. The session schema has no favorite, pin, star, bookmark, label, or tag field. There's no TUI command or API endpoint to mark a session as favorited.

To find an important session later, the user must either:

• Remember enough of the title/summary to search for it
• Save the session ID externally
• Export the session (GET /api/session/{sessionID}/export) to a file

Proposed Behavior

Add a favorite (or pinned/starred) boolean field to the session schema. How it surfaces in the API, TUI, and any future sharing/sync is open — the core ask is just that the field exists so sessions can be marked as important and filtered/ordered by it later. Any approach to utilizing it would be welcome.

Use Cases

• Long-running project sessions: a session that spans days of work (e.g., a migration or deployment) that you want to return to across multiple days
• Reference sessions: sessions with valuable research or troubleshooting context worth bookmarking
• Shared/team sessions: if session sharing lands, favorites let each user curate which shared sessions matter to them

Additional Context

This came up during a multi-day infrastructure migration where a single OpenCode V2 session contained the full cutover history. The session ID had to be saved externally (in a task note) to find it again. A built-in favorite/pin would have made this unnecessary.