Agent Duel 0.4.0-beta.6

What's Changed

• fix(arena): keep oversized file diffs reviewable by @micjm in #43
• fix(arena): wait out an offline machine instead of failing the contestant by @Qcumbeer in #40
• feat(arena): let the voter retry a failed contestant by @Qcumbeer in #44
• fix(arena): keep naming a long command after a steer is queued by @lokicik in #45
• fix(arena): state Auto Accept's reach and stop dead preview links by @lokicik in #41
• fix(arena): recover from contestant output limits by @vikas-bottomless in #38
• fix(arena): let a finished battle take a reply after the engine restarts by @lokicik in #46
• fix(arena): turn on prompt caching for Anthropic contestants by @lokicik in #48
• fix(arena): catch unreadable upstream bodies and count engine cache writes by @lokicik in #49
• chore(release): cut 0.4.0-beta.6 by @lokicik in #50

Full Changelog: v0.4.0-beta.5...v0.4.0-beta.6