v1.8.0

Added

• Powerline mode — set "powerline": true in .statusline-config.json to render each module as a background-shaded segment separated by the Nerd Font U+E0B0 (``) glyph; segments alternate between two per-theme background shades; a final trailing arrow resets to the terminal default background
• Per-theme powerline background pairs: truecolor (48;2;R;G;B) for pastel, tokyo-night, catppuccin, dracula, and nord; 256-color fallback (48;5;236/48;5;238) for mono and default
• "powerline_separator" config key to override the glyph with any string (ASCII fallback for terminals without a Nerd Font)
• Internal \033[0m resets inside segments are automatically followed by the segment's background code so colors persist throughout each segment
• Two-line layout: each line restarts the alternating segment index and gets its own trailing separator
• No behavior change when "powerline" is absent or false — output is byte-identical to the previous render path
• commands/configure.md: new step 5c asking about powerline mode with Nerd Font note and custom separator prompt
• README.md: new "Powerline mode" section after Themes with config example, Nerd Font requirement, and custom separator usage