[P3] Add a success-path unit test for ContractService.getTotalRaisedOnChain

[cyber-punk112]

Description

ContractService.getTotalRaisedOnChain(poolId) in src/contract/contract.service.ts parses a bigint (or bigint-like) value out of a simulated contract call. contract.service.spec.ts's describe('getTotalRaisedOnChain', ...) block only exercises the "returns 0n on RPC error" branch, never the branch where simulateTransaction succeeds and a real value is returned and converted to bigint.

Deliverables

• Add a test that stubs service['rpcServer'].simulateTransaction to resolve with a mock retval, and asserts getTotalRaisedOnChain returns the expected bigint
• npm run build passes

[kenzy-hue]

@kenzy-hue has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello Maintainer, I’d love to work on this project. I’m a professional, experienced, and confident in my ability to contribute high-quality work.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @kenzy-hue to this issue.

[David-282]

@David-282 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi, I'd like to work on this issue. I've reviewed the codebase and have a good understanding of the relevant area. Could you assign it to me?

ℹ️ Repo Maintainers: To accept this application, review their application or assign @David-282 to this issue.