v0.4.0

0.4.0

The cow lifecycle is complete: worktrees can now be removed by the agent, not
only created and listed. And a class of project roots that could never clone
at all — those carrying a live socket — now clone cleanly.

• remove_worktree: agent-facing removal wrapping the strategy remove
  path. The call names the worktree by name or directory (exactly one of
  the two, resolved against the inventory), refuses anything the inventory
  does not know as a cow worktree, and refuses rows whose directory is
  already gone — until upstream candidate 8 lands, a dangling row cannot be
  de-registered through the API. The landed-ness guard fails closed: HEAD
  must be an ancestor of the landing ref (origin/HEAD, else main, else
  master), or the tree must be clean with no unique commits; force: true
  bypasses the guard and the result says so.
• list_worktrees gains the missing knob (ADR 0003's dangling-row
  story). An ENOENT on a listed directory still fails the listing loudly by
  default; missing: "report" returns the row flagged missing: true
  without a derived createdAt, and missing: "prune" de-registers the row
  through the inventory's own remove (forced) and drops it from the listing.
  Any non-ENOENT stat failure remains a hard failure in every mode. Prune is
  gated on upstream candidate 8: Worktree.remove resolves the real path
  before reading the record, so a gone directory answers 400 even at force.
• Clone skips sockets, FIFOs, and device nodes (#17). A live daemon
  socket at a project root (e.g. .codegraph/daemon.sock) classified as a
  plain file, failed FICLONE with EOPNOTSUPP, and rolled the whole clone
  back — every cow clone on such a root aborted. The entries are now
  classified "special" and omitted: runtime state the clone's own daemons
  recreate, never tree content. Pinned by a real node:net unix-socket
  integration test that runs on any filesystem.

Also in this release:

• Docs: upstream candidates 9-11 filed from the 2026-09-20 field run.
• The coverage gate is green again at 100% lines on all 22 gated files:
  remove_worktree's plugin wiring (the live ctx.worktree remove calls,
  force pass-through, result text, and the prune seam) and the live git
  binding are now pinned by tests. Suite: 344 tests.