Document Blacknode product workflows and license

[temiroff]

Summary

• describe Blacknode dataset, training, robotics, vision, ROS 2, and CUDA capabilities in product-first language
• document the product-first writing rule for future agent-authored docs
• keep external names only for implemented providers, protocols, schemas, and node contracts
• standardize package license documentation with Blacknode Apache-2.0

Validation

• 15 dataset/training tests passed; 2 optional hardware-path tests skipped
• dataset and training workflow templates validated
• documentation references and git diff checks passed