docs: add Vultisig to recommended wallets

[realpaaao]

Adds Vultisig to the Recommended Wallets table in learn/wallets.mdx.

Vultisig is a free, open-source, self-custody multi-chain wallet (iOS, Android, desktop, Chrome extension). It connects to Sei as an EVM wallet: the extension announces via EIP-6963 (rdns me.vultisig), so it appears in standard EVM wallet pickers on Sei dapps.

Column notes:

• EVM ✅ / Coin Type 60 — Vultisig derives Sei on the EVM path (coin type 60), verified from the wallet's own derivation source (its coinType map resolves Sei to the Ethereum coin type).
• Auth Method "MPC / Seedless" — no mnemonic/seed phrase exists; the key is generated as shares across the user's devices (same column style as the existing "MPC / Keyless" entry).
• Mobile ✅ — native iOS + Android apps.

receipts

no runtime changes

One table row in learn/wallets.mdx; matches existing column format exactly.

[cursor]

PR Summary

Low Risk
Documentation-only table row with no application, auth, or infrastructure impact.

Overview
Adds Vultisig to the Recommended Wallets table in learn/wallets.mdx, listed as an EVM software wallet with MPC / Seedless auth, coin type 60, mobile support, and a link to vultisig.com.

No other pages or runtime code are changed.

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