theme(849): unify presets behind one palette template + bespoke AMOLED status colors (#852)

* refactor(theme): unify all presets behind one palette template

* docs(theme): update THEMES.md and AGENTS.md for the palette template

* fix(theme): restore per-preset error slot contrast, merge StatusColors into HermesStatusColors

- onErrorContainer becomes an explicit per-preset field (was derived from
  onError — same-color pairs in Gruvbox/Catppuccin light made error text
  invisible; 6 screens render this slot)
- Default dark + AMOLED onError -> White (were <3:1 on their error color)
- drop StatusColors + statusColorsOf mapper; PaletteColors.status is typed
  HermesStatusColors directly (identical field lists, pure copy ceremony)
- ThemePalette getters now by lazy; schemeFor/statusFor accessors;
  requireNotNull on the default-theme fallback (DefaultTheme is FULL)
- resolvers internal for testability

* test(theme): contrast, mode-validation, and fallback contract tests

- every shipped mode's onError/error + onErrorContainer/errorContainer
  pair meets >= 3:1 WCAG contrast (kills the error-slot regression class)
- ThemeMode init validation rejects illegal palette combinations
- AMOLED darkOnly contract + light-mode fallback to Default light

* refactor(theme): Catppuccin — named swatches from the official palette spec

Hex values verified identical (zero color drift): repeated colors (Crust,
Surface0/1, Base, Text...) now live once as named swatches matching
catppuccin.com; bespoke light primary container tints stay local.
Mocha/Latte pair unchanged.

* refactor(theme): Gruvbox — authentic bright/faded accent scheme with named swatches

Redesign per gruvbox spec: bright accents on dark bg0-bg4, faded accents
on light bg0-bg4 (correct contrast play for light mode). Named swatches,
single Gray shared across modes. Dark error pair fixed for >= 3:1
(onErrorContainer -> DarkFg1 cream, was bright red on Bg3 = 1.87:1).

* feat(theme): replace default preset with Slate — modern slate blues + teal accents

The brand default (voltage purple/amber) becomes Slate: bright teal/blue
accents on dark bg0-bg4, faded variants on light bg0-bg4. Named swatches,
single neutral gray shared across modes. Slate is also the fallback for
darkOnly/lightOnly presets (AMOLED light mode).

* feat(theme): add Nord preset — Polar Night/Snow Storm surfaces, Frost/Aurora accents

Nord's single accent set is reused across both modes (pastel accents stay
light, so on* colors use Polar Night dark text in both modes — documented
in-file). Surface ladder shares outer tiers (Nord ships 4 dark + 3 light
tones for 5 tiers). Dark error pair fixed for >= 3:1 (onErrorContainer ->
Nord6, was Nord11 on Nord2 = 2.0:1). Wired into ThemePreset, the settings
picker, and docs; default label now reads Default (Slate).

* refactor(theme): Monochrome + AMOLED — pure grayscale ramp, true-black AMOLED variant

Monochrome: every swatch R=G=B, roles by lightness only (status colors
included — documented trade-off: pair with icons/labels). AMOLED: dark-only
true-black variant (pure #000000, OLED pixels off; #121212 baseline of
Monochrome doesn't do that), containers collapse where nothing darker
exists. Both ship maximum-contrast grayscale pairs (12.8:1+ on error
slots).

* chore(theme): drop Neon Noir, finalize docs + picker label

- remove NeonNoirScheme.kt + ThemePreset.NEON_NOIR everywhere (dispatcher,
  picker, strings EN/KO, tests, AGENTS.md, THEMES.md) — 6 presets remain:
  Default, Monochrome, Gruvbox, Catppuccin, AMOLED, Nord
- picker label for the default preset is now plain 'Default'
- THEMES.md: preset conventions section (named swatches, bright/faded
  split, grayscale-status caveat, contrast test gate) + verify step runs
  testDebugUnitTest

* fix(theme): make drawer icon colors visibly follow the active preset

Selected icon now tints with the theme's primary accent (teal for Slate,
orange for Gruvbox, mauve for Catppuccin, frost-blue for Nord) instead of
onPrimaryContainer — the new presets' containers are all dark gray with
near-white text, so the selected row looked identical across themes.
Unselected icon/text colors pinned explicitly to onSurfaceVariant.

* chore(ui): remove lightning emoji from the app

- drawer title + About name: '⚡ Hermes' -> 'Hermes' (EN + KO)
- skill markers (chat self-improvement badge, memory graph): ⚡ -> 🛠
- in-progress indicators (subagent inspection): ⚡ -> 🔄

---------

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/main/java/com/m57/hermescontrol/theme/Theme.kt

@@ -2,6 +2,7 @@ package com.m57.hermescontrol.theme
 
 import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.ColorScheme
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
@@ -9,75 +10,64 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.compositionLocalOf
 import androidx.compose.ui.platform.LocalContext
-import com.m57.hermescontrol.theme.presets.AmoledDarkColorScheme
-import com.m57.hermescontrol.theme.presets.AmoledDarkStatusColors
-import com.m57.hermescontrol.theme.presets.AmoledLightColorScheme
-import com.m57.hermescontrol.theme.presets.AmoledLightStatusColors
-import com.m57.hermescontrol.theme.presets.CatppuccinDarkColorScheme
-import com.m57.hermescontrol.theme.presets.CatppuccinDarkStatusColors
-import com.m57.hermescontrol.theme.presets.CatppuccinLightColorScheme
-import com.m57.hermescontrol.theme.presets.CatppuccinLightStatusColors
-import com.m57.hermescontrol.theme.presets.DefaultDarkColorScheme
-import com.m57.hermescontrol.theme.presets.DefaultDarkStatusColors
-import com.m57.hermescontrol.theme.presets.DefaultLightColorScheme
-import com.m57.hermescontrol.theme.presets.DefaultLightStatusColors
-import com.m57.hermescontrol.theme.presets.GruvboxDarkColorScheme
-import com.m57.hermescontrol.theme.presets.GruvboxDarkStatusColors
-import com.m57.hermescontrol.theme.presets.GruvboxLightColorScheme
-import com.m57.hermescontrol.theme.presets.GruvboxLightStatusColors
-import com.m57.hermescontrol.theme.presets.MonochromeDarkColorScheme
-import com.m57.hermescontrol.theme.presets.MonochromeDarkStatusColors
-import com.m57.hermescontrol.theme.presets.MonochromeLightColorScheme
-import com.m57.hermescontrol.theme.presets.MonochromeLightStatusColors
-import com.m57.hermescontrol.theme.presets.NeonNoirDarkColorScheme
-import com.m57.hermescontrol.theme.presets.NeonNoirDarkStatusColors
-import com.m57.hermescontrol.theme.presets.NeonNoirLightColorScheme
-import com.m57.hermescontrol.theme.presets.NeonNoirLightStatusColors
+import com.m57.hermescontrol.theme.presets.AmoledTheme
+import com.m57.hermescontrol.theme.presets.CatppuccinTheme
+import com.m57.hermescontrol.theme.presets.DefaultTheme
+import com.m57.hermescontrol.theme.presets.GruvboxTheme
+import com.m57.hermescontrol.theme.presets.MonochromeTheme
+import com.m57.hermescontrol.theme.presets.NordTheme
 import kotlinx.serialization.Serializable
 
 @Serializable
 enum class ThemePreference { SYSTEM, LIGHT, DARK }
 
 @Serializable
-enum class ThemePreset { DEFAULT, MONOCHROME, GRUVBOX, CATPPUCCIN, AMOLED, NEON_NOIR }
+enum class ThemePreset { DEFAULT, MONOCHROME, GRUVBOX, CATPPUCCIN, AMOLED, NORD }
 
 val LocalThemePreference = compositionLocalOf { ThemePreference.SYSTEM }
 val LocalThemePreset = compositionLocalOf { ThemePreset.DEFAULT }
 
+/**
+ * The 6 preset themes — one file each, all built from the same
+ * [PaletteTemplate] shape (see `PaletteTemplate.kt`).
+ */
+private fun themeFor(preset: ThemePreset): ThemePalette =
+    when (preset) {
+        ThemePreset.DEFAULT -> DefaultTheme
+        ThemePreset.MONOCHROME -> MonochromeTheme
+        ThemePreset.GRUVBOX -> GruvboxTheme
+        ThemePreset.CATPPUCCIN -> CatppuccinTheme
+        ThemePreset.AMOLED -> AmoledTheme
+        ThemePreset.NORD -> NordTheme
+    }
+
 /**
  * Resolve the Material 3 [ColorScheme] for a preset + dark flag.
  *
- * Every preset exports both a dark and light scheme. AMOLED's light scheme is
- * an explicit alias of the brand default light scheme.
+ * A preset that doesn't ship the requested mode (DARK_ONLY / LIGHT_ONLY —
+ * e.g. AMOLED has no light palette) falls back to the default theme's
+ * palette for that mode.
  */
-private fun resolveColorScheme(
+internal fun resolveColorScheme(
     preset: ThemePreset,
     darkTheme: Boolean,
-) = when (preset) {
-    ThemePreset.DEFAULT -> if (darkTheme) DefaultDarkColorScheme else DefaultLightColorScheme
-    ThemePreset.MONOCHROME -> if (darkTheme) MonochromeDarkColorScheme else MonochromeLightColorScheme
-    ThemePreset.GRUVBOX -> if (darkTheme) GruvboxDarkColorScheme else GruvboxLightColorScheme
-    ThemePreset.CATPPUCCIN -> if (darkTheme) CatppuccinDarkColorScheme else CatppuccinLightColorScheme
-    ThemePreset.AMOLED -> if (darkTheme) AmoledDarkColorScheme else AmoledLightColorScheme
-    ThemePreset.NEON_NOIR -> if (darkTheme) NeonNoirDarkColorScheme else NeonNoirLightColorScheme
+): ColorScheme {
+    val theme = themeFor(preset)
+    // DefaultTheme is FULL — its scheme is never null for either mode.
+    return theme.schemeFor(darkTheme) ?: requireNotNull(DefaultTheme.schemeFor(darkTheme))
 }
 
 /**
  * Resolve the semantic status colors for a preset + dark flag.
- *
- * Every preset exports both a dark and light status set. MONOCHROME and AMOLED
- * alias the brand default status colors (they have no bespoke semantic set).
+ * Same fallback rule as the scheme.
  */
-private fun resolveStatusColors(
+internal fun resolveStatusColors(
     preset: ThemePreset,
     darkTheme: Boolean,
-) = when (preset) {
-    ThemePreset.DEFAULT -> if (darkTheme) DefaultDarkStatusColors else DefaultLightStatusColors
-    ThemePreset.MONOCHROME -> if (darkTheme) MonochromeDarkStatusColors else MonochromeLightStatusColors
-    ThemePreset.GRUVBOX -> if (darkTheme) GruvboxDarkStatusColors else GruvboxLightStatusColors
-    ThemePreset.CATPPUCCIN -> if (darkTheme) CatppuccinDarkStatusColors else CatppuccinLightStatusColors
-    ThemePreset.AMOLED -> if (darkTheme) AmoledDarkStatusColors else AmoledLightStatusColors
-    ThemePreset.NEON_NOIR -> if (darkTheme) NeonNoirDarkStatusColors else NeonNoirLightStatusColors
+): HermesStatusColors {
+    val theme = themeFor(preset)
+    // DefaultTheme is FULL — its status colors are never null for either mode.
+    return theme.statusFor(darkTheme) ?: requireNotNull(DefaultTheme.statusFor(darkTheme))
 }
 
 @Composable