v2.8.0 — Prime Agent worker

Adds Prime Agent (Prime Intellect's open-source harness) to the worker selection.

Added

• prime worker agent across the factory: m2herd-up dispatch --agent prime (pane + --headless), settings routing, SKILL §9.1 worker table.
• Headless: prime-agent -p --session-dir .m2herd/dispatch/<slice>.prime-session (plain text mode, log-tail salvage; --model only when explicitly set). Resume: watch respawns with -p -c --session-dir <same>.
• No auto-approve flag needed — prime has no per-tool approval gate (verified against binary v0.7.0).
• goal_support.md: prime row — launch-time --goal + --autonomous gates; fleet-loop re-nudges on idle.

Notes

• No herdr integration for prime yet — pane lifecycle is heuristic; prefer --headless.
• Requires Node ≥ 20.6 (curl -fsSL https://app.primeintellect.ai/prime-agent/install.sh | sh).
• Token/cost parsing deferred until prime's usage schema is verified — "no cost recorded" stays distinct from "free".
• This release also ships the previously untagged 2.7.2 changes (pi worker, .m2herd/graph.json declared topology — see CHANGELOG).

What's Changed

• fix(m2herd-up): worker panes stray to new workspaces on bind-mounted homes by @mariuszkreft in #16
• fix(m2herd-up): stop reporting a pointer that never arrived as a successful dispatch by @mariuszkreft in #17
• feat: add Prime Agent (prime) to the worker selection (2.8.0) by @mariuszkreft in #18

Full Changelog: v2.7.1...v2.8.0