v0.10.0 — team-shared rule ledgers (export)

Roadmap #3, increment 1: export measured rules to a committed, reviewable artifact so a team can version and review agent memory like code.

What's new

• /warden-share <agent> (and src/share.ts) writes an agent's active rules — body, measured token delta, context rent, and provenance — to .warden/<agent>.rules.md: a human-readable bullet list plus a machine-readable JSON block that round-trips. A PR adding a rule arrives with its proof, and a later import can re-verify it.
• Read-only and zero-coupling by design. It only reads the rule ledger and writes a file, so it cannot affect the collect/distill/select loop. Verified: nothing else imports it, and it carries the invoked-directly guard from the start.

Why export first

The risky part of team-shared ledgers is import, not export — a foreign rule claims a measured delta, and the project's one inviolable rule is "measured, not claimed." So import must re-pass the importer's own golden suite (reusing the existing selector; no new trust path). Shipping export first locks the artifact format before any import logic touches the selector.

166 tests, all green on Node 22 and 24.

Full changelog: v0.9.1...v0.10.0