feat: add prepareForSend for EVM and SVM connector

[danielbate]

• Closes FE-1490

Summary

1. Added usePrepareForSend = true flag to connectors to indicate support for the inverted flow
2. Implemented prepareForSend method in all connectors that:
   • Prepares and signs transactions
   • Returns the prepared transaction without submitting it
3. Refactored predicate-based connectors (EVM, Solana, WalletConnect) to use a shared helper method for transaction preparation

Checklist

• I've added error handling for all actions/requests, and verified how this error will show on UI. (or there was no error handling)
• I've reviewed all the copy changed/added in this PR, using AI if needed. (or there was no copy changes)
• I've included the reference to the issues being closed from Github and/or Linear (or there was no issues)
• I've changed the Docs to reflect my changes (or it was not needed)
• I've put docs links where it may be helpful (or it was not needed)
• I checked the resulting UI both in Light and Dark mode (or no UI changes were made)
• I reviewed the entire PR myself (preferably, on GH UI)

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Name	Status	Preview	Comments	Updated (UTC)
fuel-connectors	❌ Failed (Inspect)			Feb 27, 2025 11:54pm

[github-actions]

Coverage Report for Fuel Wallet (./packages/fuel-wallet)

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🔵	Branches	68.75%	22 / 32

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
packages/fuel-wallet/src/FuelWalletConnector.ts	59.91%	67.74%	56.66%	59.91%	71-78, 82-89, 93, 97-98, 101-102, 105-112, 115-116, 119-126, 129-133, 136-145, 153-154, 158-163, 206-207, 241-242, 248-265, 305-312

Generated in workflow #1476 for commit a8ed72c by the Vitest Coverage Report Action

[github-actions]

Coverage Report for Fuel Development Wallet (./packages/fuel-development-wallet)

Status	Category	Percentage	Covered / Total
🔵	Lines	100%	19 / 19
🔵	Statements	100%	19 / 19
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File Coverage

No changed files found.

Generated in workflow #1475 for commit 8df536f by the Vitest Coverage Report Action

[github-actions]

Coverage Report for Fuelet Wallet (./packages/fuelet-wallet)

Status	Category	Percentage	Covered / Total
🔵	Lines	40.9%	27 / 66
🔵	Statements	40.9%	27 / 66
🔵	Functions	33.33%	1 / 3
🔵	Branches	100%	1 / 1

File Coverage

No changed files found.

Generated in workflow #1475 for commit 8df536f by the Vitest Coverage Report Action

[LuizAsFight]

@petertonysmith94 @danielbate
makes sense to the need for this flag? the sdk could just verify if prepareForSend method exists

[petertonysmith94]

The prepareForSend method is on the abstract FuelConnector class, and therefore, this method will always exist. Open to suggestions if you have another solution for this.

[LuizAsFight]

it can't be optional?

[petertonysmith94]

As it's an abstract method on the abstract class, it can't be optional. We could introduce a new interface that the underlying connector would implement, however, this could lead to unexpected behaviours with the Fuel SDK.

interface PrepareForSendConnector {
  prepareForSend(
    address: string,
    transaction: TransactionRequestLike
  ): Promise<TransactionRequestLike>;
}

IMO the flag is simple and explicit.

[LuizAsFight]

it can't be an optional method in the abstract class?