feat: custom accent color via color wheel in settings

Add ColorWheel component (hue/saturation wheel + lightness strip + hex input).
themeStore gains accentIdx=-1 for custom mode and setCustom action.
ThemeApplier uses getActiveAccent to support both presets and custom hex.
Settings page shows "Свой" button; clicking reveals the color wheel inline.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/store/themeStore.ts

@@ -17,22 +17,50 @@ export const ACCENT_PRESETS: AccentPreset[] = [
   { name: 'Минт',     accent: '#00FFB2', rgb: '0,255,178' },
 ]
 
-const STORAGE_KEY = 'pm_accent'
+function hexToRgbStr(hex: string): string {
+  const h = hex.replace('#', '')
+  const r = parseInt(h.substring(0, 2), 16)
+  const g = parseInt(h.substring(2, 4), 16)
+  const b = parseInt(h.substring(4, 6), 16)
+  return `${r},${g},${b}`
+}
+
+const KEY_IDX    = 'pm_accent'
+const KEY_CUSTOM = 'pm_accent_custom'
 
 interface ThemeStore {
-  accentIdx: number
+  accentIdx: number   // -1 = custom color
+  customHex: string
   setAccent: (idx: number) => void
+  setCustom: (hex: string) => void
 }
 
 export const useThemeStore = create<ThemeStore>((set) => ({
   accentIdx: (() => {
     if (typeof window === 'undefined') return 0
-    const saved = localStorage.getItem(STORAGE_KEY)
+    const saved = localStorage.getItem(KEY_IDX)
     const idx = saved !== null ? parseInt(saved, 10) : 0
-    return idx >= 0 && idx < ACCENT_PRESETS.length ? idx : 0
+    return idx >= -1 && idx < ACCENT_PRESETS.length ? idx : 0
+  })(),
+  customHex: (() => {
+    if (typeof window === 'undefined') return '#ff00ff'
+    return localStorage.getItem(KEY_CUSTOM) || '#ff00ff'
   })(),
   setAccent: (idx) => {
-    if (typeof window !== 'undefined') localStorage.setItem(STORAGE_KEY, String(idx))
+    if (typeof window !== 'undefined') localStorage.setItem(KEY_IDX, String(idx))
     set({ accentIdx: idx })
   },
+  setCustom: (hex) => {
+    if (typeof window !== 'undefined') {
+      localStorage.setItem(KEY_CUSTOM, hex)
+      localStorage.setItem(KEY_IDX, '-1')
+    }
+    set({ accentIdx: -1, customHex: hex })
+  },
 }))
+
+export function getActiveAccent(accentIdx: number, customHex: string): { accent: string; rgb: string } {
+  if (accentIdx === -1) return { accent: customHex, rgb: hexToRgbStr(customHex) }
+  const preset = ACCENT_PRESETS[accentIdx] ?? ACCENT_PRESETS[0]
+  return { accent: preset.accent, rgb: preset.rgb }
+}