[Codebase Audit] Reduce panic-prone calls in `tests/mint_burn_integration.rs`

[kelly-musk]

Problem

tests/mint_burn_integration.rs contains 27 panic-prone calls (unwrap, expect, or panic!).

Evidence

• tests/mint_burn_integration.rs:41 — .expect("DATABASE_URL must be set for integration tests");
• tests/mint_burn_integration.rs:42 — PgPool::connect(&url).await.expect("db pool")
• tests/mint_burn_integration.rs:47 — Arc::new(MintBurnMetrics::new(&registry).expect("metrics"))
• tests/mint_burn_integration.rs:91 — .expect("create processed_events");
• tests/mint_burn_integration.rs:105 — .expect("create ledger_cursor");

Proposed fix

Replace non-essential unwrap/expect usages with typed error propagation and contextual logging. Keep explicit panics only where unrecoverable invariants are well-documented.

Acceptance criteria

• All avoidable panic-prone calls in this file are removed or justified with comments/tests.
• Error paths return typed errors and preserve observability context.
• Existing tests pass (or new tests cover changed paths).

[alexatsejames-alt]

@alexatsejames-alt has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi can you please assign these issue to me

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

[goodness-cpu]

@goodness-cpu has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello Maintainer, I can fix this issue.

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

[paul-itodo]

@paul-itodo has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Kindly assign

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