feat(sticker-pack): implement native sticker pack support (3-30 stickers)

Implementa suporte completo para envio de pacotes de stickers seguindo o
padrão oficial do WhatsApp (3-30 stickers por pack).

**Novos Recursos:**
- Tipos TypeScript: Sticker e StickerPack com documentação completa
- Função prepareStickerPackMessage() com criptografia AES-256-CBC + HMAC
- Conversão automática para WebP usando Sharp
- Detecção de stickers animados via VP8X header
- Deduplicação automática de stickers por hash SHA256
- Compressão ZIP usando fflate (level 0 para performance)
- Upload de thumbnail 252x252 JPEG com mesma mediaKey
- Validações conforme especificações oficiais WhatsApp

**Especificações Implementadas:**
- Mínimo 3, máximo 30 stickers (padrão oficial WhatsApp)
- Limite 1MB por sticker (hard limit)
- Recomendado: 100KB estático, 500KB animado
- Formato WebP obrigatório
- Tray icon 252x252 pixels
- Limite total pack: 30MB

**Arquivos Modificados:**
- src/Types/Message.ts: tipos Sticker e StickerPack
- src/Defaults/index.ts: media paths e HKDF keys
- src/Utils/sticker-pack.ts: implementação core (440 linhas)
- src/Utils/messages-media.ts: export getImageProcessingLibrary, mediaKey opcional
- src/Utils/messages.ts: integração com generateWAMessageContent
- src/Socket/messages-send.ts: detecção de tipo 'sticker_pack'
- package.json: dependência fflate@^0.8.2

**Segurança:**
- Criptografia AES-256-CBC com autenticação HMAC-SHA256
- HKDF key derivation para separação de chaves
- Reutilização intencional de mediaKey (protocolo WhatsApp)
- Validação de tamanhos e formatos

**Compatibilidade:**
- ✅ Não impacta mensagens interativas existentes
- ✅ Tipos completamente separados no union type
- ✅ Sharp como peer dependency opcional
- ✅ Graceful degradation se Sharp não instalado

**Uso:**
\`\`\`typescript
await sock.sendMessage(jid, {
  stickerPack: {
    name: 'Meu Pack',
    publisher: 'Autor',
    cover: coverBuffer,
    stickers: [
      { data: sticker1, emojis: ['😀'] },
      { data: sticker2, emojis: ['😎'] }
    ]
  }
})
\`\`\`

https://claude.ai/code/session_01FaRqGuPecEyPx1qiuRV8Ye

src/Types/Message.ts

@@ -39,6 +39,59 @@ import type { ILogger } from '../Utils/logger'
 export type WAMediaPayloadURL = { url: URL | string }
 export type WAMediaPayloadStream = { stream: Readable }
 export type WAMediaUpload = Buffer | WAMediaPayloadStream | WAMediaPayloadURL
+
+/**
+ * Individual sticker in a sticker pack
+ */
+export type Sticker = {
+	/** Buffer, Stream or URL of the sticker image (will be converted to WebP if needed) */
+	data: WAMediaUpload
+	/** Array of emojis associated with this sticker (max 3 recommended per WhatsApp standards) */
+	emojis?: string[]
+	/** Accessibility label for screen readers (max 125 chars for static, 255 for animated) */
+	accessibilityLabel?: string
+}
+
+/**
+ * Sticker Pack message - send a complete pack of stickers
+ *
+ * Follows WhatsApp official specifications:
+ * - 3-30 stickers per pack (enforced)
+ * - WebP format (auto-converted)
+ * - Max 100KB per static sticker, 500KB per animated (recommended, not enforced)
+ * - Either all static OR all animated (recommended)
+ *
+ * @example
+ * ```typescript
+ * await sock.sendMessage(jid, {
+ *   stickerPack: {
+ *     name: 'My Awesome Pack',
+ *     publisher: 'Your Name',
+ *     description: 'Cool stickers collection',
+ *     cover: Buffer.from(...), // or URL or Stream
+ *     stickers: [
+ *       { data: Buffer.from(...), emojis: ['😀', '😃'] },
+ *       { data: 'https://example.com/sticker.webp', emojis: ['😎'] }
+ *     ]
+ *   }
+ * })
+ * ```
+ */
+export type StickerPack = {
+	/** Array of stickers (minimum 3, maximum 30 per WhatsApp official spec) */
+	stickers: Sticker[]
+	/** Cover/tray icon for the pack (will be auto-resized to 252x252 JPEG) */
+	cover: WAMediaUpload
+	/** Pack name (max 128 characters) */
+	name: string
+	/** Publisher/author name (max 128 characters) */
+	publisher: string
+	/** Optional pack description */
+	description?: string
+	/** Optional custom pack ID (auto-generated if omitted) */
+	packId?: string
+}
+
 /** Set of message types that are supported by the library */
 export type MessageType = keyof proto.Message
 
@@ -818,6 +871,44 @@ export type AnyRegularMessageContent = (
 			 */
 			album: AlbumMessageOptions
 	  }
+	| {
+			/**
+			 * Sticker Pack - Send a complete pack of stickers (3-30 stickers)
+			 *
+			 * The pack will appear in the recipient's sticker tray, similar to official sticker packs.
+			 * All stickers are automatically converted to WebP format if needed.
+			 *
+			 * @example
+			 * ```typescript
+			 * import { readFileSync } from 'fs'
+			 *
+			 * await sock.sendMessage(jid, {
+			 *   stickerPack: {
+			 *     name: 'Emoji Pack',
+			 *     publisher: 'InfiniteAPI',
+			 *     description: 'Fun emoji stickers',
+			 *     cover: readFileSync('./pack-cover.png'),
+			 *     stickers: [
+			 *       { data: readFileSync('./sticker1.webp'), emojis: ['😀'] },
+			 *       { data: readFileSync('./sticker2.png'), emojis: ['😎', '🔥'] },
+			 *       { data: { url: 'https://example.com/sticker3.webp' }, emojis: ['🎉'] }
+			 *     ]
+			 *   }
+			 * })
+			 * ```
+			 *
+			 * **Requirements:**
+			 * - `fflate` package (installed automatically)
+			 * - `sharp` package for image processing: `yarn add sharp`
+			 *
+			 * **Specifications (WhatsApp Official):**
+			 * - Minimum 3 stickers, maximum 30 per pack
+			 * - Recommended: 100KB per static sticker, 500KB per animated
+			 * - WebP format (auto-converted from PNG/JPG/etc)
+			 * - Best practice: All stickers either static OR animated, not mixed
+			 */
+			stickerPack: StickerPack
+	  }
 	| SharePhoneNumber
 	| RequestPhoneNumber
 ) &