Challenge: Simulate PDA Derivation in Rust

Understand how Program Derived Addresses work by implementing a simplified PDA derivation algorithm using Rust's standard library hashing.

Real Solana PDAs use SHA-256 and check if the result is on the Ed25519 curve. Here we simulate this concept using DefaultHasher and check if the hash is even (our proxy for "off-curve").

Your Task

Implement find_program_address(seeds, program_id) that:

1. Iterates bumps from 255 down to 0
2. For each bump, hashes all seeds + bump + program_id together
3. Returns the first hash that is even (simulating "off-curve")
4. Returns (hash, bump) as a tuple

Requirements:

• Use std::collections::hash_map::DefaultHasher
• Hash each seed, then the bump byte, then the program_id
• Return the first even hash (hash % 2 == 0)
• This is deterministic: same seeds always produce the same result

Rust Concepts Used:

• std::hash::{Hash, Hasher} traits
• Iterating with for bump in (0..=255u8).rev()
• Tuples as return types