feat: adds extractor for epub #98

Job	Run time
Detect Changes	7s
sanitize-branch-name	2s
Build and Test Libraries (admin-api-lib)	1m 17s
Build and Test Libraries (extractor-api-lib)	2m 52s
Build and Test Services (document-extractor)	2m 10s
Build and Test Services (mcp-server)	55s
Build and Test Libraries (rag-core-api)	1m 34s
Build and Test Libraries (rag-core-lib)	1m 18s
Build and Test Services (rag-backend)	1m 14s
Build and Test Services (admin-backend)	1m 8s
Validate Infrastructure	0s
Build and Test Frontend	0s
CI Summary	5s
	12m 42s

Provide feedback