git worktree move /tmp EXDEV

Trap: moving an OpenCode worktree from /tmp/opencode into the shared worktree parent with git worktree move looks like a normal relocation. /tmp is an isolated filesystem, inaccessible to the user and often on another device, so Git fails with Invalid cross-device link. Fix: recreate the worktree in the shared parent at the same commit, transfer edits through a reviewed patch, verify byte-for-byte, then remove the isolated copy.