fix: make ANSI console text consistent with search and copy

[kelvinharron]

• Search and Copy now use the same visible text that the console renders for ANSI-colored entries.
• ANSI reset codes restore the inherited theme colors, while indexed palette color 0 remains black.
• Unknown indexed colors fall back to the console theme instead of making dark-mode text black.
• Add regression tests for search, copy, and color handling.