Update BUILD_AND_TEST.md for new structure

[Thinkersbluff]

Update build documentation to reflect new directory structure.

Tasks:

• Update all script paths to new locations
• Update Docker setup instructions with new paths
• Update examples with new directory structure
• Add troubleshooting for development environment
• Include beginner-friendly explanations alongside technical details

Acceptance Criteria:

• All build instructions work with new structure
• Docker setup functional
• Examples use correct paths
• Both novice and expert developers can follow

Dependencies: Move documentation files, Phase 2 completion
Estimate: 3 story points

[Thinkersbluff]

Accidentally created - cleaning up