OpenClaw Opik Observability Plugin Files

What's changed

Restores Opik trace export in embedded OpenClaw runs after the gateway's plugin lifecycle/architecture changes broke the plugin silently.

Fixes

• Hook registration timing — hooks are now registered at plugin registration time instead of inside start(). The OpenClaw gateway seals its hook runner after register() returns, so hooks registered in start() were silently dropped.
• Shared exporter state — mutable exporter state (Opik client, trace/span maps, flush queue) is now at module scope, so hook callbacks and start() share the same state even when OpenClaw creates different service instances.
• Missing sessionKey fallback — when agentCtx.sessionKey is absent (e.g. Nebius live gateway, Pinchbench, non-default agents), the plugin now resolves a session key via: sessionKey → sessionId → remembered agentId → last active session.
• projectName on traces — traces now correctly route to the configured project instead of silently defaulting to "Default Project".

Issues closed

Fixes [#61], [#48], [#63], [#49]