Add CI validation for bin file executable permissions

[groupsky]

Problem

Currently, there are no automated tests that verify bin files have executable permissions after build. This creates a risk that the chmod +x commands in build scripts could be accidentally removed without detection.

Context

• PR Convert @ya-modbus/emulator to TypeScript-built bin for consistency #361 standardized the emulator package build process
• All CLI packages (emulator, cli, device-profiler, mqtt-bridge) now use chmod +x in build scripts
• The chmod commands are critical - TypeScript doesn't preserve executable permissions (see TypeScript#26060)
• If chmod is removed, packages would be published with non-executable bins

Proposed Solution

Add a CI validation step in .github/workflows/ci.yml after the build step:

- name: Validate bin file permissions
  run: |
    echo "Checking bin file permissions..."
    find packages/*/dist/*/bin -name "*.js" ! -name "*.map" | while read f; do
      if [ ! -x "$f" ]; then
        echo "❌ Not executable: $f"
        exit 1
      fi
    done
    echo "✅ All bin files are executable"

Benefits

• Prevents regression where chmod is accidentally removed
• Fast check (< 1 second)
• No new dependencies needed
• Protects all 4 CLI packages

Affected Packages

• @ya-modbus/emulator
• @ya-modbus/cli
• @ya-modbus/device-profiler
• @ya-modbus/mqtt-bridge

Related

• Convert @ya-modbus/emulator to TypeScript-built bin for consistency #361 (standardized build process)
• fix(build): set executable permissions on CLI bin files #359 (added chmod to build scripts)