docs(agent): D1 — README self-update section, REUSE, CHANGELOG v0.70.0, CONTEXT

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

CONTEXT.md

@@ -5,6 +5,20 @@
 
 ## Current
 
+- **v0.70.0** (2026-07-05) — **agent self-update (operator-signed A/B slots + crash-loop
+  auto-rollback)** — TASK D1, provenance `SPIKE-agent-selfupdate-2026-07-05`. An operator-signed
+  `agent_update` op (version+sha256, sha is the only integrity root) rides the signed-jobs gate;
+  `internal/selfupdate.Executor` downloads+verifies+hands to `felhom-selfupdate-guarded apply` (root
+  re-verify → A/B atomic flip → pending marker → detached restart); the new binary commits after a
+  60s dwell; a crash-looping binary is auto-reverted by `OnFailure=felhom-agent-rollback.service`
+  (first-crash trigger [SF-1]) with the tuned `[Unit]` start-limit (120s/4) as backstop. Host
+  artifacts + sudoers `FELHOM_SELFUPDATE` + `felhom-host-install.sh` day-0 install + report field
+  `selfupdate_pending`. Green tests + companions; **live validation pending (build/publish v0.70.0,
+  manual install the artifacts on felhom-pve, then the happy-path + crash-rollback drills)**. Rollback
+  `felhom-agent.bak-0.69.0`. OPEN (v1 scope-outs): no hub-floor auto-update, no failed-update
+  auto-retry, no pending-timeout auto-rollback (a runs-but-never-commits binary is caught by
+  `host_staleness` + the pending report flag). Detail: REPORT.md.
+
 - **v0.69.0** (2026-07-04, live on felhom-pve) — **S5: host-loss DR — safe halves shipped**.
   **Part 1** `wgtunnel.InstallRecoveredKey` — writes an escrow-recovered WG privkey (create-only,
   refuse-overwrite) so the tunnel re-establishes with the SAME identity/pubkey (same /32), no keygen;