v0.5.6: deprecate animus-agent-runner-protocol

Summary

animus-cli v0.5.3 deleted the standalone agent-runner sidecar. The CLI's animus agent {run, status, cancel, control} surface now routes directly to provider plugins via SessionBackendResolver — no Unix-domain socket, no shared-secret handshake, no per-process sidecar.

As a result, animus-agent-runner-protocol has no consumer in the published animus-cli surface and no first-party agent_runner plugin will ship.

What changed

• animus-agent-runner-protocol bumped to v0.1.1 with a DEPRECATED notice in the module docs.
• Cargo manifest description prefixed with DEPRECATED —.

Compat

• The v0.1.0 wire surface remains unchanged. Existing pinned consumers (animus-cli v0.5.2 and earlier) keep working.
• New plugin authors should target the provider-plugin surface (animus-provider-protocol / animus-session-backend) instead.

Branch

Cut from v0.5.5-agent-runner (commit 8be6106).