feat: enable data compression for content

[elevran]

• Add as configuration option (single option for now is fine, might want choice of different algorithms in future).
• Can it be implemented as a filter above any storage engine and not an internal Charon or engine function? Might need to affect (e.g.,) file names to indicate compression is enabled or not (or can auto-discover from file leading bytes?).
• Need to measure the compression/decompression speeds and compression ratio to validate benefit (e.g., time to read+write uncompressed vs compress+write+read+decompress) - base on agentic traces from HuggingFace?