[FEATURE]: Allow renaming/moving a project folder while persisting session history (replacement for stale-closed #25625)

Description

This is a replacement for #25625, which was auto-closed by the stale bot after 60 days of inactivity with an invitation to open a new issue. The underlying problem is still live: #23248 (sessions becoming orphaned when the project directory is renamed) remains open, and its companion request #23249 was closed by the same bot.

Renaming or moving a project folder currently orphans all sessions of that project: history becomes unreachable from the UI because session identity is tied to the old path.

Proposal

Support renaming/moving a project folder while persisting session history, proactively rather than via manual recovery:

1. On startup (or when a configured worktree path is missing), detect that a previously known project path no longer exists.
2. Offer to re-link the orphaned sessions to the relocated folder (e.g. match by git remote URL and/or content heuristics), instead of silently dropping them out of the session list.
3. Keep the historical path as metadata so past sessions remain attributable even if re-linking is declined.

#23249 proposed an interactive migration dialog for already-orphaned sessions; this request is about preventing the orphaning in the first place by handling renames/moves as first-class events. Both can coexist: prevention for known moves, recovery for missed ones.

Why not a duplicate

#23248 describes the symptom; this proposes the proactive fix. The distinction was already made on #25625 before its closure.

Environment

• App: OpenCode Desktop 1.18.21
• OS: Microsoft Windows 11 Education, 25H2, build 26200.8875