feat: support additionalPrograms via #[codama(program(...))] directive

[amilz]

Summary

• Adds #[codama(program(name = "...", address = "..."))] directive for declaring external program ownership on first-class nodes.
• Supported on CodamaPda, CodamaInstruction, CodamaInstructions, CodamaAccount, CodamaAccounts, and CodamaErrors.
• When present, the node is wrapped in (or applied to) a ProgramNode with the given name/address. CombineModulesVisitor routes it to additionalPrograms automatically.

Usage

#[derive(CodamaPda)]
#[codama(program(name = "associatedToken", address = "ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL"))]
#[codama(seed(name = "owner", type = public_key))]
#[codama(seed(name = "tokenProgram", type = public_key))]
#[codama(seed(name = "mint", type = public_key))]
pub struct AssociatedToken;

Then reference in instructions via pda("associatedToken", program = "associatedToken", [...]). The IDL gets an additionalPrograms entry with the program's address and PDA seeds, and account defaults use pdaLinkNode with a programLinkNode reference.

Verified against an escrow program with ATA vault accounts — IDL output is correct.

How it works

• ProgramDirective parses name and address via SetOnce (same pattern as ErrorDirective)
• SetPdasVisitor: wraps PdaNode in a ProgramNode when directive present
• SetInstructionsVisitor: wraps InstructionNode (struct) or sets name/address on ProgramNode (enum)
• SetAccountsVisitor: applies to existing AccountNode or ProgramNode via apply_program_directive helper
• SetErrorsVisitor: sets name/address on ProgramNode (enum)
• CombineModulesVisitor sees non-matching public_key → routes to additional_programs

Test plan

• cargo fmt --check && cargo clippy --all-targets -- -D warnings && cargo test
• 10 new tests (3 unit + 2 PDA integration + 2 instruction + 2 account + 1 error)
• Verified IDL output against escrow program with ATA vault accounts

Closes #68

[amilz]

Pushed minor refactor based on feeback in 81 and 82

[lorisleiva]

Nice, this is looking really good! I've made some comments mainly on adding higher-level tests with modules and trying to extract some common logic on the directive itself to clean up the visitors slightly.

[amilz]

Thanks for the feedback @lorisleiva. I think we're good but lmk if the tests/refactor don't quite get at what you're thinking.

• Rebased on latest main (resolved conflicts with #[codama(skip)] directive from feat: add #[codama(skip)] directive for all enum variants #80)
• Changed ProgramDirective.name to CamelCaseString and added update_or_wrap_program_node() helper to consolidate wrapping logic across all visitors
• Extracted ProgramDirective::apply() so visitors don't repeat the attribute lookup + match pattern
• Added combine_modules_visitor tests using declare_id! + mod blocks to validate module resolution with program directives, including #[codama(program(...))] on mod blocks directly. One note: When no main program is established via SetProgramMetadataVisitor, the first ProgramNode from a program directive becomes the main program and scraps end up as additional_programs. Seems okay to me, but figured I'd flag this for your thoughts/awareness.
• Added program directive support in CombineModulesVisitor::visit_module to enable the mod-block scenario

[lorisleiva]

Perfection! Sorry for the late reply. Just a small test request but good to merge otherwise! 🙌

[amilz]

Awesome. Thanks @lorisleiva. Added that additional test. Should be gtg.

[lorisleiva]

Thank you! will publish a new set of crates today.

[lorisleiva]

@amilz New crates published! 🚀