TUI crash: undefined is not an object (evaluating 'a.background.a')

Description

The opencode TUI crashed with an unexpected error.

Error: undefined is not an object (evaluating 'a.background.a')

Environment

• opencode version: 1.18.11
• OS: macOS 25.5.0 (arm64)
• Terminal: ghostty 1.3.1

Steps to Reproduce

Reported automatically from the opencode crash screen. (TUI was in normal use when it crashed.)

Stack Trace

TypeError: undefined is not an object (evaluating 'a.background.a')
    at nr (/$$bunfs/root/chunk-k157avrj.js:2:99335)
    at cr (/$$bunfs/root/chunk-k157avrj.js:2:105115)
    at fa (/$$bunfs/root/chunk-k157avrj.js:2:104527)
    at <anonymous> (/$$bunfs/root/chunk-k157avrj.js:2:122379)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at F (/$$bunfs/root/chunk-g290w9zp.js:2:3993)
    at init (/$$bunfs/root/chunk-k157avrj.js:2:121883)
    at provider (/$$bunfs/root/chunk-k157avrj.js:2:116982)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at children (/$$bunfs/root/chunk-k157avrj.js:2:117118)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14138)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at F (/$$bunfs/root/chunk-g290w9zp.js:2:3993)
    at vJ (/$$bunfs/root/chunk-g290w9zp.js:2:7957)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14080)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at dJ (/$$bunfs/root/chunk-g290w9zp.js:2:3567)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14072)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:19878)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at F (/$$bunfs/root/chunk-g290w9zp.js:2:3993)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at children (/$$bunfs/root/chunk-k157avrj.js:2:117118)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14138)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at F (/$$bunfs/root/chunk-g290w9zp.js:2:3993)
    at vJ (/$$bunfs/root/chunk-g290w9zp.js:2:7957)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14080)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at dJ (/$$bunfs/root/chunk-g290w9zp.js:2:3567)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:14072)
    at b (/$$bunfs/root/chunk-g290w9zp.js:2:6673)
    at <anonymous> (/$$bunfs/root/chunk-g290w9zp.js:2:19878)
    at mJ (/$$bunfs/root/chunk-g290w9zp.js:2:9650)
    at p (/$$bunfs/root/chunk-g290w9zp.js:2:9431)
    at ZJ (/$$bunfs/root/chunk-g290w9zp.js:2:11057)
    at rJ (/$$bunfs/root/chunk-g290w9zp.js:2:11931)
    at yZ (/$$bunfs/root/chunk-g290w9zp.js:2:11333)
    at w (/$$bunfs/root/chunk-g290w9zp.js:2:11238)
    at e (/$$bunfs/root/chunk-k157avrj.js:2:113598)
    at <anonymous> (/$$bunfs/root/chunk-0585s4am.js:2:22331)
    at processTicksAndRejections (native:7:39)

Additional Context

Custom agent color configuration in opencode.json:

"agent": {
  "build": { "color": "secondary" },
  "plan": { "color": "warning" },
  "advise": { "color": "accent" },
  "explore": { "color": "success" },
  "general": { "color": "error" }
}

The crash appears to originate from the TUI rendering layer (Ink/React reconciler) when trying to access a .background property on what is likely a color/theme value that is undefined.