feat: add approved spender

[Birdmannn]

Reward Pool Contract

A Soroban smart contract for managing a reward pool with admin-controlled spender whitelisting.

Features

Initialize

Sets up the contract with an admin and reward token.

initialize(admin: Address, token: Address)

• Stores admin address in instance storage
• Stores token address in instance storage
• Emits PoolInitialized event
• Panics if already initialized or auth fails

Add Approved Spender

Whitelists a contract address to spend from the reward pool.

add_approved_spender(admin: Address, spender: Address)

• Validates admin authorization
• Stores spender in persistent storage
• Emits SpenderAdded event
• Panics if not initialized, unauthorized, or auth fails

Storage

• Instance Storage: Admin, Token
• Persistent Storage: Spender(Address) → bool

Events

• PoolInitialized(admin, token) - Emitted on initialization
• SpenderAdded(spender) - Emitted when spender is whitelisted

Testing

Run tests:

cargo test

All tests include:

• Initialization success/failure scenarios
• Spender whitelisting with proper authorization
• Unauthorized access prevention
• Event emission verification

This PR closes #23

[Birdmannn]

the cargo.toml was adjusted to tell rust-analyzer not to analyse the target folder. minor change.

[Kaylahray]

Amazing. Thanks