hl frontends: 3 more logos (slash, topdog, markets-mobile)

[Flotapponnier]

Summary

• slash: slash.trade/logo.png (662x662 PNG, dark mark, needs light chip in dark mode)
• topdog: hl.eco/logos/topdog.jpg (400x400 JPG, fully colored — Telegram bot, no site)
• markets-mobile: markets.xyz/assets/brand/markets/markets-logomark-wordmark-dark.svg (Markets by Kinetiq, wordmark SVG, needs light chip in dark mode)
• Registry entries for the 3 so /products/slash, /products/topdog, /products/markets-mobile render real descriptions
• Skipped (agent couldn't identify): shax, cipher, stryx, perpswld — none surface as HL frontends on hl.eco, flowscan, hypurr, or in coverage. Their /products pages fall back to initials chips