Teleport: Pack an agent session, resume it anywhere on any harness

Teleport packages a coding-agent session into a zip containing SUMMARY.md, FILES.md, LEARNINGS.md, a RESUME.md with restore instructions, optional uncommitted.patch, raw history, and an unpack script, making the bundle harness-agnostic. The install script detects supported harnesses (Claude, Cursor, Codex, OpenCode, Goose, Pi), adds a /teleport command to create the zip, and allows unpacking on any machine—without Teleport installed—so the agent can resume the session after applying patches or checking out branches.