Add regression coverage for UpgradeStatus failure handling

[attyolu]

##closes #1087

Summary

• Add regression coverage for UpgradeStatus handling in ContractUpgradeOrchestratorService.
• Verify RPC rejection statuses are persisted as failed upgrades and exposed through the existing 503 error contract.
• Cover successful PENDING submission and boundaries for unapproved upgrades and missing dry-run results.

Validation

• Focused orchestrator test file: 40 tests passed.
• TypeScript diagnostics for the changed service and test files: none.
• Full test suite: not completed; the run was cancelled.
• Repository-wide lint/build checks reported unrelated existing failures. Targeted lint reported only pre-existing any usages elsewhere in the test file.

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