Fix build.yml: Auto-commit binaries to repository and improve build robustness

[Copilot]

Problem

The GitHub Actions workflow had two critical issues:

1. Binaries not accessible in repository: While builds were succeeding, compiled STREAM binaries were only stored as workflow artifacts and never committed to the repository's main branch, making them inaccessible to users.

2. Poor build resilience: Individual architecture build failures could impact the overall workflow stability, and there was limited visibility into which specific architectures failed.

Solution

Automated Binary Commits

Added comprehensive Git automation to the collect job that:

• Configures Git credentials for automated commits
• Collects all successfully built binaries into the bin/ directory
• Automatically commits and pushes binaries to the main branch after each successful build
• Generates detailed commit messages with build statistics

- name: Configure Git for automated commits
  run: |
    git config --local user.email "action@github.com"
    git config --local user.name "GitHub Action"

- name: Commit and push binaries to repository
  run: |
    if [[ $(git status --porcelain bin/) ]]; then
      git add bin/
      git commit -m "🚀 Auto-build: Update STREAM binaries from workflow run ${{ github.run_number }}"
      git push origin HEAD:main
    fi

Enhanced Build Robustness

• Graceful failure handling: Individual architecture failures no longer break the entire workflow
• Multiple compilation fallbacks: Added progressive fallback strategies for difficult architectures
• Comprehensive error tracking: Failed builds create marker files for debugging
• Better architecture reporting: Generates detailed coverage reports showing which architectures succeeded/failed

Improved Artifact Management

• Enhanced artifact collection to include failure logs
• Better binary organization and naming
• Automatic executable permissions for binaries
• Comprehensive build statistics and architecture coverage reports

Result

After these changes:

• ✅ Binaries are directly accessible from the repository's bin/ directory on the main branch
• ✅ No more workflow artifacts dependency - users can download binaries directly from the repo
• ✅ Robust multi-architecture builds with graceful failure handling
• ✅ Comprehensive build reporting with success/failure tracking for all architectures
• ✅ Automatic repository updates after each successful build run

The workflow now properly addresses both the compilation robustness and binary accessibility issues, making the repository much more useful for end users who want direct access to STREAM binaries across all supported architectures.

Fixes: Issues with build artifact accessibility and workflow resilience
Testing: Verified with local STREAM compilation and workflow syntax validation

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