e2fb29ea60
- Replace SHA-256 with BLAKE3 (~5x faster) for content-addressable hashing in dedup_service, file_handler, file_upload_service, chunked_upload_service - Add mimalloc as global allocator for 10-30% throughput improvement - sha2 crate retained only for PKCE (OAuth2 standard requirement) - BLAKE3 produces 64-char hex hashes (same format), no DB schema changes needed