feat(copilot): added 1st instruction draft

.github/copilot-instructions.md

@@ -0,0 +1,161 @@
+# HomeRacker Copilot Instructions
+
+## Project Overview
+HomeRacker is a fully modular 3D-printable rack-building system designed for versatile "racking needs" including server racks, shoe racks, bookshelves, and more. The project consists of:
+
+- **HomeRacker Core**: Open-spec modular building system (MIT License)
+- **3D Models**: Parametric and non-parametric models in OpenSCAD and Fusion 360 formats (CC BY 4.0)
+- **Automation Scripts**: Fusion 360 export scripts for batch model generation
+- **GitHub Pages Site**: Documentation and showcase website
+
+## Core Technologies & Frameworks
+- **3D Modeling**: OpenSCAD (parametric), Fusion 360 (.f3d files)
+- **Languages**: SCAD (OpenSCAD), Python (Fusion 360 scripts)
+- **Dependencies**: BOSL2 library for OpenSCAD
+- **Web**: GitHub Pages with Jekyll (Architect theme)
+- **Standards**: 10" and 19" rack specifications, custom HomeRacker dimensions
+
+## Key Components Architecture
+### Building Blocks
+1. **Supports**: Vertical structural elements with standardized connection points
+2. **Connectors**: 6-way connection system for supports (front/back, left/right, up/down)
+3. **Lock Pins**: Securing mechanism for assembled connections
+4. **Rebar**: Horizontal structural reinforcement elements
+5. **Splints**: Additional reinforcement components
+
+### Models Structure
+- `/models/rackmount_ears/`: Fully customizable rackmount ears (OpenSCAD)
+- `/models/gridfinity/`: Gridfinity-compatible base plates
+- `/models/flexmount/`: Flexible mounting solutions
+- `/models/shelf/`: Parametric shelf components
+- `/models/wallmount/`: Wall mounting brackets
+
+## Development Guidelines
+
+### OpenSCAD Best Practices
+- Use BOSL2 library for advanced geometric operations
+- Set `$fn=100` for smooth curves in production models
+- Implement parametric designs with customizer-friendly variables
+- Group parameters logically with `/* [Section Name] */` comments
+- Provide sensible defaults and value ranges for sliders
+- Include sanity checks for critical parameters
+- Use descriptive variable names following `CONSTANT_CASE` for constants
+
+### File Organization
+- Keep `.scad` files in appropriate `/models/` subdirectories
+- Include example images showing customization options
+- Maintain `README.md` files explaining each model's purpose
+
+### Documentation Standards
+- Use emoji headers for visual organization (🔧, ✨, 📐, etc.)
+- Include clear assembly instructions with diagrams
+- Provide printing tips and material recommendations
+- Document all customizable parameters
+- Include real-world use case examples
+
+### Code Quality
+- Comment complex geometric calculations
+- Use meaningful module names
+- Separate configuration from implementation
+- Test parameter ranges for edge cases
+- Validate dimensional accuracy against rack standards
+
+## Project-Specific Context
+
+### HomeRacker Core Dimensional Standards
+- **Base Unit**: 15mm (core measurement for all HomeRacker components)
+- **Lock Pin Side**: 4mm (square profile for pins and matching holes)
+- **Wall Thickness**: 2mm (standard connector wall thickness)
+- **Standard Tolerance**: 0.2mm (added to connector interiors for print variances)
+- **Support Dimensions**: 15mm x 15mm base, height = multiples of 15mm
+- **Connector Centers**: Always 1 base unit (15mm) in height
+- **Lock Pin Edge Distance**: 5.5mm from support edges
+- **Standard Chamfer**: 1mm for printability
+
+### Licensing Requirements
+- Source code: MIT License (commercial use allowed)
+- 3D models & assets: CC BY 4.0 (attribution required, share-alike)
+- Always include proper license headers in new files
+- Credit original work when modifying existing models
+
+### Brand Guidelines
+- Use "HomeRacker" (not "Home Racker" or "home-racker") 
+- Include HomeRacker logo overlay on compatible model thumbnails
+- Maintain consistent visual style across documentation
+- Reference Makerworld links for published models
+
+## Common Tasks & Patterns
+
+### Creating New Models
+1. Start with parametric design in OpenSCAD
+2. Use BOSL2 library for complex operations
+3. Include customizer parameters with proper grouping
+4. Test with common device dimensions
+5. Export STL files for immediate use
+6. Document parameters and use cases
+7. Add example images showing variations
+
+### Fusion 360 Scripts
+- Place scripts in `/scripts/` with proper manifest files
+- Include usage instructions in README.md
+- Test export functionality across parameter ranges
+- Validate output file naming conventions
+
+### Documentation Updates
+- Update main README.md for new features
+- Include visual examples with actual photos
+- Link to Makerworld models where applicable
+- Maintain table of contents structure
+
+## Self-Improvement Instructions
+
+### When Encountering Wrong Turns
+If you find yourself making incorrect assumptions or heading down the wrong path during development assistance:
+
+1. **Pause and Reassess**: Stop the current approach and explicitly state what went wrong
+2. **Gather Context**: Re-read project documentation, examine existing code patterns, and understand the specific use case better
+3. **Ask Clarifying Questions**: Request specific details about requirements, constraints, or expected outcomes
+4. **Document the Learning**: Add insights to these instructions for future reference
+
+### Instruction Enhancement Protocol
+When updating these instructions based on new learnings:
+
+1. **Preserve Core Structure**: Maintain the organized sections and GitHub best practices format
+2. **Add Specific Examples**: Include concrete code snippets or configuration examples that caused confusion
+3. **Update Technology Stack**: Keep dependencies, tools, and version requirements current
+4. **Expand Edge Cases**: Document unusual scenarios or parameter combinations that need special handling
+5. **Validate Changes**: Ensure new instructions don't conflict with existing project patterns
+
+### Learning from Mistakes
+Common areas for improvement:
+- **Dimensional Accuracy**: Double-check rack standards and measurement conversions
+- **Parameter Validation**: Ensure SCAD parameters have proper bounds and error checking
+- **File Naming**: Follow established conventions for exports and derivatives
+- **License Compliance**: Verify all new content uses appropriate licensing
+- **Cross-Platform Compatibility**: Consider Windows/Linux/macOS differences in file paths and tools
+
+### Feedback Integration
+When receiving feedback about incorrect suggestions:
+1. Acknowledge the specific error made
+2. Explain the corrected approach
+3. Update relevant sections of these instructions
+4. Test the corrected approach before suggesting it again
+
+## Troubleshooting Common Issues
+
+### OpenSCAD Problems
+- **Rendering Issues**: Check for overlapping geometry, invalid meshes, or extreme parameter values
+- **BOSL2 Errors**: Verify library installation and include statements
+- **Performance**: Reduce `$fn` for development, increase for final exports
+
+### Export Script Issues  
+- **Fusion 360 API**: Check for API version compatibility and parameter access methods
+- **File Paths**: Use cross-platform path handling in Python scripts
+- **Batch Operations**: Implement proper error handling for automated exports
+
+### Documentation Sync
+- **Broken Links**: Validate all external references to Makerworld and GitHub
+- **Image References**: Ensure all images exist and use correct relative paths
+- **Version Mismatches**: Keep model versions synchronized between repository and published versions
+
+Remember: HomeRacker is about modularity, openness, and practical maker solutions. Always consider how suggestions support these core principles while maintaining professional engineering standards.