Adds a new selectable theme `terminal` (alongside System / Whale / Whale
Light / Grayscale / Catppuccin / Tokyo Night / Dracula / Gruvbox) that
paints every surface with `Color::Reset` instead of any RGB so the
host terminal's own background, foreground, and palette show through.
The existing `system` theme only chose between two RGB themes (Whale dark
or Whale Light) based on COLORFGBG / macOS appearance — useful, but it
still painted brand-colored RGB surfaces. Users with custom terminal
themes (Solarized, Nord, transparent backgrounds, custom Ghostty/iTerm
schemes) had no way to make the TUI respect their terminal palette.
Implementation:
- New `TERMINAL_UI_THEME` const where every `*_bg` and most text slots
are `Color::Reset`, and accents (mode_agent/yolo/plan, status_working,
status_warning) use ANSI named colors so they also inherit the user's
terminal palette rather than DeepSeek brand RGB.
- `ThemeId::Terminal` plumbed through `from_name` / `name` /
`display_name` / `tagline` / `ui_theme` / `SELECTABLE_THEMES`, and
registered in `normalize_theme_name` with aliases `term`,
`transparent`, `follow-terminal`, `inherit` so existing
user-friendly config strings just work.
- `theme_remap_active(Terminal) → true` so the existing per-cell remap
in `ColorCompatBackend` rewrites every hard-coded palette constant
(`DEEPSEEK_INK`, `DEEPSEEK_SLATE`, `BORDER_COLOR`, `TEXT_BODY`, …) to
`Color::Reset`. Without this, the many render sites that reach for
the named palette constants directly would still paint brand RGB.
- `theme_green` / `theme_red` return `Color::Green` / `Color::Red`
for Terminal so diff "+"/"−" stay green/red but follow the user's
terminal palette.
- `theme_diff_added_bg` / `theme_diff_deleted_bg` return `Color::Reset`
for Terminal — diff highlight is conveyed by foreground color only.
- The new theme is the second entry in `SELECTABLE_THEMES` (right after
System) so it surfaces prominently in the `/theme` picker.
theme_picker tests: the new theme is inserted in row 2 of
`SELECTABLE_THEMES`, which shifts the indices three existing tests
relied on — `arrow_down_previews_next_theme`,
`enter_commits_with_persist_true`, and `digit_jumps_to_row` — so those
expectations are updated to match the new ordering. No production
behavior change in those tests, just index arithmetic.
Default (`theme = "system"`) is unchanged; existing users see no
difference. Users who want full terminal pass-through opt in via
`/theme` or `theme = "terminal"` in settings.toml.
liushiao
0ea84dce7d