Add OpenClaw unwrap flow and non-blocking proxy startup

fix(openclaw): wait for proxy before gateway routing

fix(openclaw): route codex through headroom proxy

fix(openclaw): normalize engine messages for discord

refactor(openclaw): DRY up duplicate code across plugin

Harden openclaw plugin proxy handling and metadata

OpenClaw plugin fixes, telemetry fix, cost tracker improvement, tokenBudget support

feat: add OpenClaw ContextEngine plugin (@headroom-ai/openclaw)