fix(sticker): align sticker pack with WABA Android behavior (Frida capture)

Align sticker pack implementation with WhatsApp Business Android (WABA)
behavior captured via Frida reverse engineering. Fixes 4 critical issues
identified in field-by-field comparison with WABA's sticker DB schema.

- Add Lottie/WAS format detection (isLottieBuffer) for animated stickers
- Fix mimetype: use 'application/was' for Lottie, 'image/webp' for WebP
- Fix isLottie: auto-detect instead of hardcoded false
- Fix tray icon: convert cover to PNG format (WABA uses .png, not .webp)
- Add 512x512 dimension enforcement for WebP stickers (WABA standard)
- Add isLottie field to Sticker type for explicit format override

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

src/Types/Message.ts

@@ -54,12 +54,14 @@ 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) */
+	/** Buffer, Stream or URL of the sticker image (WebP or Lottie/WAS format) */
 	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
+	/** Force Lottie format detection (auto-detected if omitted) */
+	isLottie?: boolean
 }
 
 /**