feat(maestro): add nine editor-theme TUI palettes

Solarized (dark/light), Catppuccin Mocha, GitHub (dark/light),
Tokyo Night, Gruvbox, Nord, Dracula. Colours auto-tuned from the
canonical seeds to clear the palette contrast floors; tests now
assert every RGB preset, not just dark/light.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/INSTALL.md

@@ -134,7 +134,7 @@ cover every v1 action — only override what you want to change:
 
 ```toml
 [tui]
-theme = "dark"              # dark (default), light, or ansi
+theme = "dark"              # see the theme list below
 leader = "ctrl-a"            # one byte that escapes Insert mode
 chord_timeout_ms = 1000      # how long to hold a partial chord like `ctrl-w`
 
@@ -154,6 +154,22 @@ chord_timeout_ms = 1000      # how long to hold a partial chord like `ctrl-w`
 `theme` selects the complete TUI palette. `dark` is the default and follows
 Maestro's terminal-native dark product palette; `light` is its light peer;
 `ansi` uses the terminal's named ANSI colours for terminals without truecolour.
+The remaining presets adapt well-known editor themes, with individual colours
+lifted or darkened where the originals fall short of the WCAG AA contrast
+floors the palette tests assert:
+
+| name              | based on         |
+|-------------------|------------------|
+| `solarized-dark`  | Solarized Dark   |
+| `solarized-light` | Solarized Light  |
+| `catppuccin`      | Catppuccin Mocha |
+| `github-dark`     | GitHub Dark      |
+| `github-light`    | GitHub Light     |
+| `tokyo-night`     | Tokyo Night      |
+| `gruvbox`         | Gruvbox Dark     |
+| `nord`            | Nord             |
+| `dracula`         | Dracula          |
+
 An unknown name is rejected as an `[tui].theme` configuration error.
 
 The full action vocabulary is the `Action` enum in