MAINNET-DAY-0 says registering and shielding need no proof, but apply_actions always validates one

[Immadominion]

MAINNET-DAY-0.md says:

What needs no proof at all: registering a viewing key, and shielding. Both are ordinary public transactions. A headless service can move value into the pool today with nothing but an RPC URL

I do not think that is right, and it is the kind of thing that costs a team a day.

apply_actions calls validate_proof unconditionally, before it does anything else:

fn apply_actions(
    ref self: ContractState,
    actions: Span<ServerAction>,
    screening: Option<ScreeningAttestation>,
) {
    self.reentrancy_guard.start();
    self.pausable.assert_not_paused();
    self.validate_proof(:actions);
    ...

and validate_proof starts with:

let mut proof_facts_span = execution_info.tx_info.proof_facts;
assert(!proof_facts_span.is_empty(), errors::EMPTY_PROOF_FACTS);

There is no branch on the action types. apply_actions is also the only non-admin write entrypoint on the contract, so as far as I can tell every state change needs a proof, registration and shielding included.

That matches what I observed building against the Sepolia pool: SetViewingKey and a shield both had to go through compile_actions, a prover, and then apply_actions with proof and proof_facts attached. Without them the submission does not get as far as reverting.

If there is a route I have missed I would like to know, since it would make the first mainnet transactions much cheaper to reach. But if the doc is out of date it is worth fixing: it currently tells teams they can write to the pool with only an RPC URL, and that is where the eligibility transactions have to happen.