fix(ui): use picker.select instead of vim.ui.select to fix snacks picker bug

[aweis89]

Summary

This PR fixes an issue with Snacks.nvim picker when using vim.ui.select. The bug causes an "Invalid 'height': Number is not integral" depending on the picker's config.

Related issue: folke/snacks.nvim#2539

Changes

• Added a picker.select() function that uses Snacks.picker directly when Snacks is the preferred picker, bypassing the buggy vim.ui.select implementation
• For all other pickers (Telescope, FZF-Lua, mini.pick), falls back to vim.ui.select to respect user customizations (e.g., dressing.nvim)
• Replaced vim.ui.select calls with picker.select() in files that use selection UI

Files Changed

• lua/opencode/ui/picker.lua - Added select() and _snacks_select() functions
• lua/opencode/api.lua - Use picker.select for agent selection
• lua/opencode/provider.lua - Use picker.select for model selection
• lua/opencode/git_review.lua - Use picker.select for file selection
• lua/opencode/ui/input_window.lua - Use picker.select for confirmation prompts
• lua/opencode/ui/ui.lua - Use picker.select for session selection

[sudo-tee]

Thanks for the PR.

I will have a look this weekend