solana: Add comments and lint directives for governance entrypoint

Add function documentation and some clarifying notes about how the
governance program works
Add linting directives for cargo dylint to ignore ownership checks in a
particular case

solana/programs/wormhole-governance/src/instructions/governance.rs

@@ -9,7 +9,7 @@
 //! instruction is able to invoke the program's admin instructions.
 //!
 //! The instruction needs to be encoded in the VAA payload, with all the
-//! accounts. These accounts may be in any order, with two placeholder accounts:
+//! accounts. These accounts may be in any order and must include two additional placeholder accounts:
 //! - [`OWNER`]: the program will replace this account with the governance PDA
 //! - [`PAYER`]: the program will replace this account with the payer account
 use anchor_lang::prelude::*;
@@ -124,21 +124,32 @@ impl From<AccountMeta> for Acc {
     }
 }
 
+/// Processes a VAA [wormhole_anchor_sdk::wormhole::PostedVaa] sent to this program via a Guardian set.
+/// The VAA's payload contains an instruction and relevant Accounts that it requires. This program
+/// performs verification of the VAA's contents and then performs a Cross Program Invocation if all
+/// verification succeeds.
+/// NOTE: `missing_owner_check` is disabled here: The VAA instruction is expected to contain
+/// placeholder accounts with Pubkeys set to hard-coded values [OWNER] and [PAYER]. These keys are
+/// overwritten. Because they are placeholders, the `owner` field is not important.
+#[allow(unknown_lints)]
+#[allow(missing_owner_check)]
 pub fn governance<'info>(ctx: Context<'_, '_, '_, 'info, Governance<'info>>) -> Result<()> {
     let vaa_data = ctx.accounts.vaa.data();
 
     let mut instruction: Instruction = vaa_data.clone().into();
 
-    // Iterate over a copy of all accounts provided in the VAA payload. 
+    // Iterate over a copy of all accounts provided in the VAA payload.
     // If the Pubkey for an account is equal to the hard-coded OWNER constant, overwrite with the
     // governance program's Pubkey.
     // If the Pubkey for an account is equal to the hard-coded PAYER constant, overwrite with the
     // payer program account's pubkey. (This must also be the Signer for the creator of the
     // Governance account.)
     instruction.accounts.iter_mut().for_each(|acc| {
         if acc.pubkey == OWNER {
+            // Missing ownership check is OK here
             acc.pubkey = ctx.accounts.governance.key();
         } else if acc.pubkey == PAYER {
+            // Missing ownership check is OK here
             acc.pubkey = ctx.accounts.payer.key();
         }
     });