authn: remove the local agent-token plane The agent_token table and everything that minted, verified, listed or revoked it. Agent credentials are tokens.sr.ht working tokens now: signed, expiring, owned by a meta.sr.ht account and carrying grants, verified locally by sr-ht-ecore's bearer package. One door, and nothing behind it — a credential the instance plane refuses is refused, where it used to be offered to a second store that might say yes. DEPLOY GATE: do not deploy this until every agent configured with the shared secret holds a tokens.sr.ht token with spec:propose (spec:read to read). Migration 0005 drops the table, migrate-on-upgrade runs it on deploy, and deploying early locks out every agent at once — including the SSH push path. hooks/ no longer reads agent_token directly. The push path goes through the same authn.Resolver the HTTP surfaces use and demands spec:propose, because a push by an agent is a proposal by another transport. The refs rule and the provenance requirement are untouched on both counts: a universal grant is still only an agent to the receive path, and X-Agent / X-Agent-Session are still mandatory on every agent write. bearer.ErrNotOurs is now a permanent refusal. A meta.sr.ht PAT used to fall through to the local store and miss there; with no store to fall through to it earns a 401 rather than the 503 an unclassified error would. [tokens.sr.ht] origin becomes a required config key: with no issuer there is no credential to check, so the daemon fails startup instead of serving reads and refusing every agent write one request at a time. /tokens redirects to the daemon that issues (tokens SPEC ch. 7).
feat(authn): unified-login identity, agent token validation, provenance trailers Cookie identity is fail-open to anonymous: a missing, tampered or foreign-key cookie yields no user rather than an error, so anonymous browsing never breaks on a bad cookie. Agent tokens are the opposite. A bad bearer is a permanent 401, a store outage a transient 503, and revoked rows are returned so operators can distinguish a killed token from one that never existed. TokenStore is declared here rather than imported from db/, so the two packages can be built in parallel and service/ wires them together.