Adds TrustTransport as the third interface on the shared NostrConnection,
completing the social-layer happy path in the spike:
- WebOfTrust: pure, Flutter-free Duniter membership rule (N certs from members +
within distance D of bootstrap referents), iterated to a fixpoint. The
commons_core-worthy piece; TDD'd (threshold, distance cutoff, transitive
growth, expired/revoked/self exclusion).
- NostrTrustTransport: certifications as a custom addressable kind (30777,
keyed by issuer+subject) — certify renews, revoke replaces, certs expire.
- Trust filters spam (network-trust §2): seeds certify Alice; Eve stays
uncertified; Bob discovers both offers and annotates authors — Alice known,
Eve unknown — all over ONE shared connection.
Findings updated: WoT risk High -> Medium (policy/bootstrap, not feasibility);
overall scope Medium-High -> Medium — all three transport contracts now proven.
30 tests green, analyzer clean, Block 1 untouched.
