v0.2.1 — Hermes registration compatibility

Compatibility fix

Registration now checks the actual host PlatformEntry signature. Only the optional parse_target_ref_fn callback is omitted when unsupported. ACL, configuration and standalone-send callbacks remain registered; unrelated TypeErrors still surface. A warning explains that lane-qualified outbound targets require a host supporting the callback.

Verification

• 335 plugin tests passed on Hermes v2026.9.14 and the catalog PR checkout.
• New real plugin-loader tests cover both the current API and an enforced missing-field contract.
• GitHub CI now covers main and v2026.9.14 through the canonical test runner; both jobs passed.
• Published-source plugin validation passed, including security scan: safe.

This release also includes the previously published main-branch work since v0.2.0: callback controls, optional reactions, invocation settings, persistent-keyboard settings, bounded attachment intake and fallback message-history polling. The existing default-on fallback poller and its explicit environment disable switch are now documented and declared in optional_env; its behavior is unchanged by this fix.

These are offline checks, not a live VK inbound/outbound smoke report. The reporter's exact Hermes build is still unknown. This fallback does not promise compatibility with every older release or restore lane-qualified target support to hosts without that API.