Add STATE_VERSION to all settlement PDA seeds

[kaze-cow]

Description

Updates the settlement root PDA seed to correspond to the Major and minor cargo package versions

Contents

Generally speaking the root state PDA is now:

macro_rules! state_version {
    () => { concat!(env!("CARGO_PKG_VERSION_MAJOR"), ".", env!("CARGO_PKG_VERSION_MINOR")) };
}

pub const SETTLEMENT_SEED: &[u8] = concat!("settlement v", state_version!()).as_bytes();

The whole seed is printable ASCII, so it shows up readably in explorers, logs and solana account output instead of trailing a raw byte. At 15 bytes it has ample headroom under the 32-byte MAX_SEED_LEN, which a test now pins.

No CU cost. Everything resolves in rustc — strings on the built .so shows settlement v0.1 baked into rodata — so nothing happens on-chain. The four extra seed bytes are free too: sol_create_program_address and sol_try_find_program_address charge a flat create_program_address_units (1500 CU) per bump attempted, before the seeds are even read out of program memory, so cost never scales with seed length.

Other considerations

• User delegations stop working. Users delegate their token accounts to the state PDA, and a bump moves that address, so every user has to delegate again.
• Whatever the buffers still hold is stranded. A buffer's funds are only spendable by the state PDA that is its SPL authority. After a bump the program can no longer sign for the old state PDA, so those funds can never be moved again. Buffers must be drained under the old program version first.

How to test

Check new strategy

🤖 Generated with Claude Code

[linear-code]

SC-287