[SDK] Add ipfsQuote nodeCall helper

[tcsenpai]

Repository: ../sdks

Add a helper method to get IPFS cost quote before building transaction.

Files to modify

• src/websdk/demosclass.ts - Add ipfsQuote method

Implementation

/**
 * Get a cost quote for an IPFS operation without submitting a transaction.
 * Use this to populate tx.content.custom_charges before signing.
 * 
 * @param fileSize - Size of file in bytes
 * @param operation - 'add' or 'pin'
 * @returns Cost quote with breakdown
 */
async ipfsQuote(fileSize: number, operation: 'add' | 'pin' = 'add'): Promise<IpfsQuote> {
    return this.nodeCall("ipfsQuote", { fileSize, operation })
}

Verification

• bun run build in ../sdks must pass
• Commit and push to SDK repo
• WAIT for user to publish new SDK version before continuing