bug: Opencode defaults to black opencode theme and removes "system" theme if launched from nvim

[wtsiamruk]

Did you check docs and existing issues?

• I am using the latest plugin version
• I read the plugin docs
• I read the opencode docs
• I searched the existing plugin issues
• I searched the existing opencode issues

:checkhealth opencode output

==============================================================================
opencode: 1 ⚠️

opencode.nvim ~

• OS: Darwin 25.4.0 (arm64)
• nvim version: 0.12.1.
• opencode.nvim git commit hash: eb1be3208251a61d4a61fdd5870301003012ce50.
• vim.g.opencode_opts: {}

opencode.nvim [binaries] ~

• ✅ OK opencode available with version 1.4.11.
• ✅ OK curl available.
• ✅ OK pgrep available.
• ✅ OK lsof available.

opencode.nvim [snacks] ~

• ⚠️ WARNING snacks.nvim is not available: ask() and select() will not be enhanced.

Describe the bug

When i open opencode from the nvim it doesn't use the terminal system theme, video showcasing the bug, there are related opencode issues, they are closed though.

anomalyco/opencode#11151

bug-report.mov

Steps To Reproduce

1. install kitty
2. install nvim
3. install catpuccin-latte theme on kitty and nvim
4. setup the opencode.nvim plugin
5. Open the session, exit the session, open the sesion again (all using the preconf shortcut)

Expected Behavior

opencode opens as from within kitty and uses kitty's theme as system theme.