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>

AGENTS.md

@@ -200,8 +200,12 @@ breakdown, edge cases, and timeline of previous occurrences.
 ### Theme
 
 `Theme.kt` uses a preset-based theme system with 6 built-in presets: Default,
-Monochrome, Gruvbox, Catppuccin, AMOLED, and Neon Noir. Each preset provides both
-light and dark color schemes plus matching semantic status colors.
+Monochrome, Gruvbox, Catppuccin, AMOLED, and Nord. Each preset provides light
+and dark color schemes plus matching semantic status colors (AMOLED is
+dark-only — light mode falls back to the default theme).
+Every preset is a `ThemePalette` template fill (`PaletteTemplate.kt`): raw
+`PaletteColors` + `HermesStatusColors` mapped into the Material 3
+`ColorScheme` slots, with the error slots derived from the status set.
 
 Dynamic color (Material You on API 31+) is controlled by a `useDynamicColors`
 parameter on `HermesControlTheme`, not a compile-time constant. When dynamic
@@ -288,7 +292,7 @@ com.m57.hermescontrol/
 │   └── ws/         HermesWsClient, JSON-RPC models, WsEvent, BillingRepository
 ├── notification/   ChatNotificationService, NotificationReplyReceiver
 ├── theme/          Color, Theme, Motion, Spacing, Shapes, Type, HermesStatusColors
-│   └── presets/    Default, Monochrome, Gruvbox, Catppuccin, AMOLED, NeonNoir
+│   └── presets/    Default, Monochrome, Gruvbox, Catppuccin, AMOLED, Nord
 ├── ui/
 │   ├── common/     HermesScaffold, StateViews, SharedComponents, DetailDialog, DetailRows
 │   └── 28 feature packages (achievements, analytics, authlogin, billing, channels,