feat(theme): expand color palette for richer UI semantics

Add new theme colors across all four color schemes (Flexoki Dark,
Catppuccin Mocha, Tokyo Night, Terminal) to enable more nuanced
visual states:

Surface variants:
- SurfaceHover: Highlighted surface for active tabs, selected rows
- SurfaceBright: Extra emphasis for focused elements

Border variants:
- BorderBright: Prominent borders for cards and focus states
- BorderAccent: Accent-colored borders for active/selected elements

Accent variants:
- AccentBright: Higher contrast accent for emphasis
- AccentDim: Muted accent for subtle backgrounds

New semantic colors:
- Magenta: Session-related metrics
- Cyan: Token-related metrics

These additions provide the foundation for visual polish work across
components and tabs, enabling icon coloring, gradient effects, and
proper background fill without relying solely on the base accent color.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/tui/theme/theme.go

@@ -6,89 +6,139 @@ import "github.com/charmbracelet/lipgloss"
 // Theme defines the color roles used throughout the TUI.
 type Theme struct {
 	Name          string
-	Background  lipgloss.Color
+	Background    lipgloss.Color // Main app background
-	Surface     lipgloss.Color
+	Surface       lipgloss.Color // Card/panel backgrounds
-	Border      lipgloss.Color
+	SurfaceHover  lipgloss.Color // Highlighted surface (active tab, selected row)
-	TextDim     lipgloss.Color
+	SurfaceBright lipgloss.Color // Extra bright surface for emphasis
-	TextMuted   lipgloss.Color
+	Border        lipgloss.Color // Subtle borders
-	TextPrimary lipgloss.Color
+	BorderBright  lipgloss.Color // Prominent borders (cards, focus)
-	Accent      lipgloss.Color
+	BorderAccent  lipgloss.Color // Accent-colored borders for focus states
+	TextDim       lipgloss.Color // Lowest contrast text (hints, disabled)
+	TextMuted     lipgloss.Color // Secondary text (labels, metadata)
+	TextPrimary   lipgloss.Color // Primary content text
+	Accent        lipgloss.Color // Primary accent (links, active states)
+	AccentBright  lipgloss.Color // Brighter accent for emphasis
+	AccentDim     lipgloss.Color // Dimmed accent for backgrounds
 	Green         lipgloss.Color
+	GreenBright   lipgloss.Color
 	Orange        lipgloss.Color
 	Red           lipgloss.Color
 	Blue          lipgloss.Color
+	BlueBright    lipgloss.Color
 	Yellow        lipgloss.Color
+	Magenta       lipgloss.Color
+	Cyan          lipgloss.Color
 }
 
 // Active is the currently selected theme.
 var Active = FlexokiDark
 
-// FlexokiDark is the default theme.
+// FlexokiDark is the default theme - warm, paper-inspired dark theme.
 var FlexokiDark = Theme{
 	Name:          "flexoki-dark",
 	Background:    lipgloss.Color("#100F0F"),
 	Surface:       lipgloss.Color("#1C1B1A"),
-	Border:      lipgloss.Color("#282726"),
+	SurfaceHover:  lipgloss.Color("#282726"),
+	SurfaceBright: lipgloss.Color("#343331"),
+	Border:        lipgloss.Color("#403E3C"),
+	BorderBright:  lipgloss.Color("#575653"),
+	BorderAccent:  lipgloss.Color("#3AA99F"),
 	TextDim:       lipgloss.Color("#575653"),
-	TextMuted:   lipgloss.Color("#6F6E69"),
+	TextMuted:     lipgloss.Color("#878580"),
 	TextPrimary:   lipgloss.Color("#FFFCF0"),
 	Accent:        lipgloss.Color("#3AA99F"),
+	AccentBright:  lipgloss.Color("#5BC8BE"),
+	AccentDim:     lipgloss.Color("#1A3533"),
 	Green:         lipgloss.Color("#879A39"),
+	GreenBright:   lipgloss.Color("#A3B859"),
 	Orange:        lipgloss.Color("#DA702C"),
 	Red:           lipgloss.Color("#D14D41"),
 	Blue:          lipgloss.Color("#4385BE"),
+	BlueBright:    lipgloss.Color("#6BA3D6"),
 	Yellow:        lipgloss.Color("#D0A215"),
+	Magenta:       lipgloss.Color("#CE5D97"),
+	Cyan:          lipgloss.Color("#24837B"),
 }
 
-// CatppuccinMocha is a warm pastel theme.
+// CatppuccinMocha is a warm pastel theme with soft, soothing colors.
 var CatppuccinMocha = Theme{
 	Name:          "catppuccin-mocha",
 	Background:    lipgloss.Color("#1E1E2E"),
 	Surface:       lipgloss.Color("#313244"),
-	Border:      lipgloss.Color("#45475A"),
+	SurfaceHover:  lipgloss.Color("#45475A"),
+	SurfaceBright: lipgloss.Color("#585B70"),
+	Border:        lipgloss.Color("#585B70"),
+	BorderBright:  lipgloss.Color("#7F849C"),
+	BorderAccent:  lipgloss.Color("#89B4FA"),
 	TextDim:       lipgloss.Color("#6C7086"),
 	TextMuted:     lipgloss.Color("#A6ADC8"),
 	TextPrimary:   lipgloss.Color("#CDD6F4"),
 	Accent:        lipgloss.Color("#89B4FA"),
+	AccentBright:  lipgloss.Color("#B4D0FB"),
+	AccentDim:     lipgloss.Color("#293147"),
 	Green:         lipgloss.Color("#A6E3A1"),
+	GreenBright:   lipgloss.Color("#C6F6C1"),
 	Orange:        lipgloss.Color("#FAB387"),
 	Red:           lipgloss.Color("#F38BA8"),
 	Blue:          lipgloss.Color("#89B4FA"),
+	BlueBright:    lipgloss.Color("#B4D0FB"),
 	Yellow:        lipgloss.Color("#F9E2AF"),
+	Magenta:       lipgloss.Color("#F5C2E7"),
+	Cyan:          lipgloss.Color("#94E2D5"),
 }
 
-// TokyoNight is a cool blue/purple theme.
+// TokyoNight is a cool blue/purple theme inspired by Tokyo city lights.
 var TokyoNight = Theme{
 	Name:          "tokyo-night",
 	Background:    lipgloss.Color("#1A1B26"),
 	Surface:       lipgloss.Color("#24283B"),
-	Border:      lipgloss.Color("#414868"),
+	SurfaceHover:  lipgloss.Color("#343A52"),
+	SurfaceBright: lipgloss.Color("#414868"),
+	Border:        lipgloss.Color("#565F89"),
+	BorderBright:  lipgloss.Color("#7982A9"),
+	BorderAccent:  lipgloss.Color("#7AA2F7"),
 	TextDim:       lipgloss.Color("#565F89"),
 	TextMuted:     lipgloss.Color("#A9B1D6"),
 	TextPrimary:   lipgloss.Color("#C0CAF5"),
 	Accent:        lipgloss.Color("#7AA2F7"),
+	AccentBright:  lipgloss.Color("#A9C1FF"),
+	AccentDim:     lipgloss.Color("#252B3F"),
 	Green:         lipgloss.Color("#9ECE6A"),
+	GreenBright:   lipgloss.Color("#B9E87A"),
 	Orange:        lipgloss.Color("#FF9E64"),
 	Red:           lipgloss.Color("#F7768E"),
 	Blue:          lipgloss.Color("#7AA2F7"),
+	BlueBright:    lipgloss.Color("#A9C1FF"),
 	Yellow:        lipgloss.Color("#E0AF68"),
+	Magenta:       lipgloss.Color("#BB9AF7"),
+	Cyan:          lipgloss.Color("#7DCFFF"),
 }
 
-// Terminal uses ANSI 16 colors only.
+// Terminal uses ANSI 16 colors only - maximum compatibility.
 var Terminal = Theme{
 	Name:          "terminal",
 	Background:    lipgloss.Color("0"),
 	Surface:       lipgloss.Color("0"),
+	SurfaceHover:  lipgloss.Color("8"),
+	SurfaceBright: lipgloss.Color("8"),
 	Border:        lipgloss.Color("8"),
+	BorderBright:  lipgloss.Color("7"),
+	BorderAccent:  lipgloss.Color("6"),
 	TextDim:       lipgloss.Color("8"),
 	TextMuted:     lipgloss.Color("7"),
 	TextPrimary:   lipgloss.Color("15"),
 	Accent:        lipgloss.Color("6"),
+	AccentBright:  lipgloss.Color("14"),
+	AccentDim:     lipgloss.Color("0"),
 	Green:         lipgloss.Color("2"),
+	GreenBright:   lipgloss.Color("10"),
 	Orange:        lipgloss.Color("3"),
 	Red:           lipgloss.Color("1"),
 	Blue:          lipgloss.Color("4"),
+	BlueBright:    lipgloss.Color("12"),
 	Yellow:        lipgloss.Color("3"),
+	Magenta:       lipgloss.Color("5"),
+	Cyan:          lipgloss.Color("6"),
 }
 
 // All available themes.