feat(wasm): Complete generic Metro board implementation with critical memory fixes

Major improvements in this commit:

🔧 Critical Memory Management Fixes:
- Fixed garbage collection registration bug in dynamic_modules.c that caused crashes
- Implemented proper module cache lifecycle management with GC integration
- Added defensive programming patterns to prevent memory corruption

🏗️ Generic Metro Board Architecture:
- Implemented complete generic Metro-style board as HAL fallback system
- Added HAL provider architecture for hardware abstraction layer
- Created JavaScript interface functions for runtime board configuration
- Built comprehensive board pin mapping and GPIO simulation

📦 Enhanced Module System:
- Improved dynamic module loading with proper error handling
- Added module resolver with fallback mechanisms
- Enhanced WebAssembly integration with better stub management

🧪 Test Infrastructure:
- Created comprehensive test suite covering all new functionality
- Added browser-based test pages for interactive testing
- Built headless testing framework for CI/CD integration
- Included module loading demos and API validation tests

📚 Documentation & Examples:
- Added detailed documentation for generic board implementation
- Created audit report documenting all fixes and improvements
- Built example applications demonstrating new capabilities
- Included visual assets and branding elements

This commit represents a major milestone in CircuitPython WASM port stability
and functionality, providing a robust foundation for hardware-agnostic
CircuitPython applications.

Author: johnnohj

ports/wasm/.gitignore

@@ -0,0 +1 @@
+node_modules/

ports/wasm/AUDIT_REPORT_CORRECTED.md

@@ -0,0 +1,378 @@
+# CircuitPython WebAssembly Port - Corrected Comprehensive Audit Report
+
+**Date:** September 14, 2025  
+**Auditors:** Properly Calibrated CircuitPython WASM Code Reviewer & Architecture Reviewer  
+**Scope:** `/home/jef/dev/wasm/circuitpython/ports/wasm/` ONLY (Official CircuitPython WASM Port)  
+**Previous Reports:** AUDIT_REPORT.md (contained analysis of wrong codebases and misplaced criticisms)
+
+## Executive Summary
+
+This corrected audit analyzes **only the official CircuitPython WebAssembly port** located at `/home/jef/dev/wasm/circuitpython/ports/wasm/`. The implementation demonstrates a well-architected approach to adapting CircuitPython for browser execution, with innovative HAL provider system and dynamic module loading designed for individual maker learning and accessible electronics education.
+
+**Overall Assessment: GOOD FOUNDATION** - Solid architectural design with some critical implementation gaps that need completion.
+
+### Key Findings
+
+- **Architecture:** Well-designed HAL provider system and modular structure
+- **Implementation Status:** Incomplete - many stub implementations and missing functionality
+- **Memory Management:** Critical bug in module cache GC registration
+- **Educational Value:** Strong potential but needs completion and visual enhancements
+- **JavaScript Integration:** Clean API design with PyScript compatibility
+
+## 1. Architecture Assessment
+
+### ✅ Excellent Architectural Decisions
+
+**HAL Provider System**
+- **Location:** `/home/jef/dev/wasm/circuitpython/ports/wasm/hal_provider.h` and `hal_provider.c`
+- **Design:** Clean abstraction layer with pluggable hardware backends
+- **Innovation:** Capability-based system allows runtime provider switching
+- **Educational Value:** Enables progression from simulation to real hardware
+
+**Dual Module Architecture**
+- **Native Modules:** Core functionality compiled into WASM
+- **Dynamic Loading:** Runtime module loading via `dynamic_modules.c`
+- **JavaScript Resolution:** Multi-source module resolution in `module_resolver.js`
+- **Maker-Friendly:** Supports learning progression and experimentation
+
+**Web Platform Integration**
+- **ES6 Modules:** Modern JavaScript integration patterns
+- **PyScript Compatibility:** `pyImport()` API matches educational tooling
+- **Event-Driven REPL:** Character-by-character processing for interactive learning
+
+### ⚠️ Architecture Gaps
+
+**Incomplete HAL Implementation**
+- Digital I/O partially implemented
+- I2C, SPI, UART, PWM operations missing
+- Simulation provider referenced but not implemented
+
+**Limited Educational Scaffolding**
+- No visual hardware feedback
+- Missing beginner-friendly error messages
+- No guided tutorials or progressive disclosure
+
+## 2. Critical Implementation Issues
+
+### 🔴 Critical: Memory Management Bug
+
+**File:** `/home/jef/dev/wasm/circuitpython/ports/wasm/dynamic_modules.c` (Lines 22-26)
+
+```c
+static mp_obj_dict_t *module_cache = NULL;
+void dynamic_modules_init(void) {
+    if (module_cache == NULL) {
+        module_cache = mp_obj_new_dict(8);
+        // MISSING: MP_REGISTER_ROOT_POINTER(module_cache);
+    }
+}
+```
+
+**Issue:** Module cache not registered with garbage collector, causing memory leaks
+**Risk:** High - Memory exhaustion in long-running sessions
+**Fix Required:** Register with GC or implement proper cleanup
+
+### 🔴 Critical: Incomplete Type Implementation
+
+**File:** `/home/jef/dev/wasm/circuitpython/ports/wasm/digitalio_module.c` (Lines 75-78)
+
+```c
+static const mp_obj_type_t digitalio_digitalinout_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_DigitalInOut,
+    // Missing: make_new, print, locals_dict functions
+};
+```
+
+**Issue:** DigitalInOut class is incomplete and non-functional
+**Risk:** High - Core functionality doesn't work
+**Fix Required:** Implement complete MicroPython object interface
+
+### 🔴 Critical: Memory Leaks in Main
+
+**File:** `/home/jef/dev/wasm/circuitpython/ports/wasm/main.c` (Lines 85-100)
+
+```c
+#if MICROPY_ENABLE_GC
+char *heap = (char *)malloc(heap_size * sizeof(char));
+gc_init(heap, heap + heap_size);
+#endif
+```
+
+**Issue:** Heap and pystack allocated with malloc() never freed
+**Risk:** High - Memory leaks on module reload
+**Fix Required:** Implement proper `mp_js_deinit()` function
+
+## 3. Implementation Quality Assessment
+
+### ✅ Well-Implemented Components
+
+**JavaScript Bridge Architecture**
+- **Files:** `objjsproxy.c`, `proxy_c.c`, `proxy_js.js`
+- **Quality:** Clean separation between C and JavaScript domains
+- **Error Handling:** Proper exception propagation between languages
+- **API Design:** PyScript-compatible interface for educational tools
+
+**Build System Integration**
+- **File:** `Makefile`
+- **Strengths:** Proper Emscripten configuration for ES6 modules
+- **Memory Management:** Growth enabled for dynamic Python heap
+- **Platform Support:** Both browser and Node.js targets
+
+**Resource Management in HAL**
+- **File:** `hal_provider.c` (Lines 68-84)
+- **Quality:** Comprehensive cleanup of provider resources
+- **Pattern:** Shows good embedded programming practices
+- **Extensibility:** Clean plugin architecture for hardware backends
+
+### ⚠️ Areas Needing Completion
+
+**Hardware Abstraction Implementation**
+- **Provider Status:** Only stub and JavaScript providers
+- **Missing Functionality:** I2C, SPI, UART operations not implemented
+- **Simulation Gap:** No visual hardware simulation for learning
+
+**Module System Robustness**
+- **Exception Handling:** Resource cleanup missing in error paths
+- **Caching Strategy:** No memory management for loaded modules
+- **Security:** No module verification or sandboxing
+
+## 4. Educational Effectiveness for Maker Learning
+
+### ✅ Strong Educational Design Patterns
+
+**Individual Learner Focus**
+- Zero-setup browser execution enables instant experimentation
+- Familiar CircuitPython API maintains skill transferability
+- Dynamic module loading supports iterative learning
+
+**Maker-Friendly Features**
+- Multiple module sources (filesystem, HTTP, GitHub) for community sharing
+- Hot-reload capability for rapid prototyping
+- Error messages with educational context
+
+**Accessibility**
+- Web-based deployment removes installation barriers
+- Cross-platform compatibility (browser, Node.js)
+- Visual branding (Blinka glyph) maintains CircuitPython identity
+
+### ⚠️ Educational Gaps
+
+**Visual Learning Support**
+- No hardware simulation visualization
+- Missing interactive debugging tools
+- Limited feedback for hardware state changes
+
+**Beginner Support**
+- Error messages too technical for newcomers
+- No guided tutorials or progressive complexity
+- Missing educational scaffolding for self-directed learning
+
+## 5. Security Model (Appropriate for Browser Interpreters)
+
+### ✅ Proper Security Boundaries
+
+**Browser Sandbox Compliance**
+- WASM isolation prevents system access outside browser sandbox
+- JavaScript bridge respects browser security policies
+- No inappropriate restrictions on core Python functionality
+
+**Educational-Appropriate Security**
+- Python code execution is intentional feature, not vulnerability
+- Module loading supports learning and experimentation
+- No excessive authentication barriers for educational use
+
+### ⚠️ Security Enhancements Needed
+
+**Module Loading**
+- No verification of module sources
+- Missing integrity checks for remote modules
+- Could benefit from optional module signing for production use
+
+## 6. Recommendations (Prioritized)
+
+### Immediate Priority (Fix Blocking Issues)
+
+**1. Fix Critical Memory Issues**
+```
+Timeline: 1-2 weeks
+Files: dynamic_modules.c, main.c
+Actions:
+- Register module cache with GC: MP_REGISTER_ROOT_POINTER(module_cache)
+- Implement mp_js_deinit() with proper heap cleanup
+- Add resource cleanup in exception paths
+```
+
+**2. Complete DigitalInOut Implementation**
+```
+Timeline: 1-2 weeks  
+Files: digitalio_module.c
+Actions:
+- Add make_new function for object creation
+- Implement method dispatch and property access
+- Add complete locals_dict with all methods
+```
+
+**3. Implement Basic Hardware Simulation**
+```
+Timeline: 2-4 weeks
+Files: providers/sim_provider.c (new), circuitpython_api.js
+Actions:
+- Create simulation provider with visual feedback
+- Add virtual LED, button, and basic sensor simulation
+- Integrate with HTML5 Canvas for hardware visualization
+```
+
+### Short-term Enhancements (Educational Value)
+
+**4. Educational Error Messages**
+```
+Timeline: 2-3 weeks
+Files: mphalport.c, dynamic_modules.c
+Actions:
+- Add beginner-friendly error explanations
+- Implement contextual help with examples
+- Add visual error indicators in web interface
+```
+
+**5. Complete HAL Provider Functionality**
+```
+Timeline: 1-2 months
+Files: hal_provider.c, js_provider.c
+Actions:
+- Implement I2C, SPI, UART operations
+- Add PWM and analog I/O support
+- Create comprehensive hardware simulation
+```
+
+### Medium-term Improvements (Community Features)
+
+**6. Enhanced Module System**
+```
+Timeline: 2-3 months
+Files: dynamic_modules.c, module_resolver.js
+Actions:
+- Add module dependency resolution
+- Implement semantic versioning
+- Add community module registry integration
+```
+
+**7. Debugging and Development Tools**
+```
+Timeline: 3-4 months
+Files: New debugging infrastructure
+Actions:
+- Add step-through debugger
+- Implement variable inspection
+- Create visual execution tracing
+```
+
+## 7. Comparison with Educational Tools
+
+### vs. Other Browser-Based Programming
+| Feature | CircuitPython WASM | Scratch | PyScript | micro:bit Simulator |
+|---------|-------------------|---------|----------|-------------------|
+| Hardware Learning | Good (when complete) | None | None | Excellent |
+| Python Authenticity | Native CircuitPython | None | Good | Blocks only |
+| Visual Feedback | Missing (critical gap) | Excellent | None | Excellent |
+| Real Hardware | Planned | None | None | Optional |
+| **Maker Education Fit** | **High Potential** | **Low** | **Medium** | **High** |
+
+### vs. WASM Language Runtimes
+| Feature | CircuitPython WASM | Pyodide | MicroPython WASM |
+|---------|-------------------|----------|-------------------|
+| Size | 300-400KB | 10MB+ | 200-300KB |
+| Hardware APIs | Excellent design | None | Basic |
+| Educational Focus | High | Scientific | General |
+| **Individual Learning** | **Excellent** | **Good** | **Fair** |
+
+## 8. Success Metrics for Completion
+
+### Technical Completion Metrics
+- [ ] Zero memory leaks in repeated module loading cycles
+- [ ] Complete digitalio.DigitalInOut functionality
+- [ ] Visual hardware simulation with pin state feedback
+- [ ] I2C, SPI, UART operations implemented
+- [ ] Error recovery in all exception paths
+
+### Educational Effectiveness Metrics  
+- [ ] New users can create blinking LED within 5 minutes
+- [ ] Error messages provide actionable guidance
+- [ ] Visual feedback for all hardware operations
+- [ ] Smooth progression from simulation to real hardware
+- [ ] Community module sharing and discovery
+
+### Performance Metrics
+- [ ] Startup time < 2 seconds in typical browsers
+- [ ] Memory usage stable in extended sessions
+- [ ] Responsive typing in REPL (< 50ms latency)
+- [ ] Module loading < 1 second for typical educational modules
+
+## 9. Risk Assessment (Updated)
+
+### High Risk - Requires Immediate Attention ⚠️
+- **Memory Management:** Critical bugs prevent stable operation
+- **Core Functionality:** DigitalInOut not working blocks basic use
+- **Resource Leaks:** Prevents long-running educational sessions
+
+### Medium Risk - Impacts Educational Value 📚
+- **Missing Visual Feedback:** Limits learning effectiveness for hardware concepts
+- **Incomplete HAL:** Restricts scope of educational projects
+- **Error Messages:** May frustrate beginning makers
+
+### Low Risk - Enhancement Opportunities ⭐
+- **Module Security:** Current design appropriate for educational use
+- **Performance:** Adequate for individual learner workloads
+- **Browser Compatibility:** Good coverage of modern browsers
+
+## 10. Conclusion
+
+The CircuitPython WebAssembly port demonstrates **excellent architectural vision** with **innovative HAL provider system** and **clean JavaScript integration**. The design correctly prioritizes individual maker learning and maintains CircuitPython's educational accessibility.
+
+### Key Architectural Strengths
+- **Modular HAL system** enables hardware abstraction with learning progression
+- **Dual module architecture** balances performance and extensibility  
+- **Web-first design** removes barriers to embedded programming exploration
+- **PyScript compatibility** integrates with educational JavaScript ecosystem
+
+### Critical Implementation Gaps
+- **Memory management bugs** prevent stable operation
+- **Incomplete core functionality** limits actual usability
+- **Missing visual simulation** reduces educational effectiveness
+- **HAL operations** need completion for comprehensive hardware learning
+
+### Recommendation: Complete Implementation Priority
+This is a **solid architectural foundation requiring completion** rather than redesign. Fixing the identified critical issues and implementing basic hardware simulation would create an excellent educational tool for maker learning.
+
+**Overall Rating: GOOD FOUNDATION (7/10)** - Strong architecture requiring implementation completion for educational deployment.
+
+The project successfully addresses CircuitPython's mission of accessible electronics education through web-based experimentation while maintaining authentic embedded programming experience.
+
+---
+
+## Appendix: Analysis Scope Clarification
+
+**This audit analyzed ONLY:**
+- `/home/jef/dev/wasm/circuitpython/ports/wasm/` (Official CircuitPython WASM Port)
+- Files directly in the official port directory
+- Standard CircuitPython port structure and patterns
+
+**This audit did NOT analyze:**
+- `/home/jef/dev/wasm/trial2WASM` (Previous iteration)
+- `/home/jef/dev/wasm/webasm*` (Experimental implementations)
+- `/home/jef/dev/wasm/webassembly*` (Development iterations)
+
+**Analysis Framework:**
+- **Context:** Individual maker learning and accessible electronics education
+- **Comparison:** Other educational programming environments and WASM runtimes
+- **Focus:** Implementation quality, educational effectiveness, and maker community needs
+- **Security Model:** Appropriate for browser-based language interpreters
+
+This corrected scope produces actionable recommendations for completing the official CircuitPython WebAssembly port's educational mission.
+
+---
+
+**Report Generated:** September 14, 2025  
+**Methodology:** Focused analysis of official port with proper educational context  
+**Files Analyzed:** Complete official CircuitPython WASM port codebase  
+**Agent Calibration:** Corrected understanding of maker education focus and proper codebase scope