hub: accept controller agent_channel_* events (channel-health relay) v0.20.0

The controller v0.90.0 channel-health checker pushes agent_channel_* events to /api/v1/event;
the allowedEventTypes allowlist rejected them (HTTP 400). Added the 8 types (operator-only).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EPZ4GJ8L5Jqf8UiPwbn1kt

hub/CHANGELOG.md

@@ -1,5 +1,14 @@
 # Felhom Hub — Changelog
 
+## v0.20.0 — Accept controller `agent_channel_*` events (channel-health relay) (2026-06-29)
+
+Companion to felhom-controller v0.90.0's controller→agent channel health-check. The controller pushes
+classified `agent_channel_*` events to `/api/v1/event`, but the handler's `allowedEventTypes`
+allowlist rejected them (HTTP 400). Added the 8 types (`pin_mismatch`, `unauthorized`, `unreachable`,
+`timeout`, `misconfigured`, `construction_error`, `unknown`, `recovered`) so the operator relay works.
+These are **operator-only** (not customer notification toggles, same as the host_* events); the
+existing dispatcher routes them generically (no template change). Version `0.19.0 → 0.20.0`.
+
 ## v0.19.0 — Agent capability-degraded operator alert (HostCapabilityChecker) (2026-06-29)
 
 Companion to felhom-agent v0.44.0's privileged-capability self-probe: the agent now rides a