refactor: const string contract methods

[SimonRastikian]

Closes #2140 and #950

[SimonRastikian]

@DSharifi, I discovered locally that I do not have jq and ruff packages installed while running locally cargo make check-all-fast.
After installing them, the command works so I can debug locally.
Pinging you bcz not sure if we want to add these to nix env too?

[SimonRastikian]

In this PR, I tackled hopefully all the contract methods (including the one where #[private] is mentioned above).
It was mainly generated with Claude, however I reiterated several times over it and read it in a meticulous manner verifying each function name and making sure nothing is left over by mistake (I used regex over the files). However, a couple pair of eyes would not hurt :)

[claude]

Review: refactor: const string contract methods

Clean refactor - centralizing method name strings into contract_interface::method_names is a good improvement for maintainability.

Minor issue (non-blocking): Two "propose_update" string literals were missed:

• crates/devnet/src/mpc.rs:479 - still uses "propose_update" instead of method_names::PROPOSE_UPDATE
• crates/contract/tests/sandbox/common.rs:305 - still uses "propose_update" instead of method_names::PROPOSE_UPDATE

The constant values in method_names.rs are correct and match the actual contract function names. The README fix (start_resharing_instance to start_reshare_instance) correctly reflects the actual method name.

No critical issues found. Approved.

[gilcu3]

Thank you!

My only suggestion is to use the new const directly in crates/node/src/indexer.rs

[SimonRastikian]

I went manually through all the functions and added constants. Some are not used but still chose to add the corresponding constant (e.g. VERSION). This is only to allow a better visibility over the API

[kevindeforth]

Nice, thank you!

[SimonRastikian]

@claude review

[claude]

Review: refactor: const string contract methods

No critical issues found. This is a clean mechanical refactor centralizing contract method name strings into contract_interface::method_names. All constant values have been verified to match the actual contract function names. The previously flagged missed propose_update occurrences have been addressed in subsequent commits.

✅ Approved