fix(status): refresh lazy providers and environment visibility

[mehalter]

Icon providers

• Recheck the cached no-provider state when MiniIcons or nvim-web-devicons loads later.
• Preserve the fast no-provider path until a supported provider becomes available.

Virtual environments

• Use matching visibility rules in the surround condition and rendered provider.
• Treat empty environment variables as absent and allow a named Conda environment to remain visible.
• Honor global and component-local Conda options, including ignore_base = false.
• Preserve custom surround conditions and explicit condition = false.

Validation

• Passed StyLua, Selene, typos, Lua compilation, and diff checks.
• Passed focused icon-provider and virtual-environment regressions on Neovim 0.11.0 and 0.12.4.