Ipc unit test expansion

[gitsofaryan]

fixes : #107
cc : @d4v1d03

Summary

This PR expands IPC unit test coverage and refactors the erasure coding implementation to reliably support large files. It also ensures the SDK's internal download flow properly utilizes the new erasure coding strategy.

Key Highlights

• Expanded Test Coverage: Added 13 new IPC unit tests, increasing coverage from 40 → 53.
• Comprehensive Scenarios: Covered download flows, upload internals, erasure decoding, error cases, and access control.
• Large File Support: Refactored erasure coding to a row-based Reed–Solomon strategy, fixing failures on large files.
• SDK Integration Fix: Added the missing extract_data_blocks decode logic into IPC.download_chunk_blocks (sdk/sdk_ipc.py) to actually execute the erasure coding during chunk downloads.
• Test Suite Compatibility: Updated mock signatures in test_sdk_ipc.py (e.g., adding missing pool arguments) to ensure the test suite is 100% compatible with the actual SDK ConnectionPool API.
• Improved Decoding: Improved decoding error handling and cleaned up production code.
• Configuration Defaults: Added sensible defaults (max_concurrency, block_part_size, use_connection_pool) to SDKConfig.
• Deterministic CI: Restored hardcoded private key in the integration test for deterministic CI behavior.

Validation

• ✅ All 53 IPC unit tests pass (verified locally against actual SDK API)
• ✅ All 38 erasure code tests pass
• ✅ Integration upload test verified

📸 Test & Coverage Snapshots

IPC Unit Tests – Detailed Coverage	Erasure Code & Integration Test Results