v1.1.24

Maintenance: update bundled external tools and package versions (#98)

Version management:
- Bump Docker 28.3.0, Docker Compose v2.37.2, Buildx v0.33.0, Go 1.26
- Add external-tool-versions.json as single source of truth for
  Docker Engine, Docker Compose, Docker Buildx and Go versions
- Add update-versions.ps1 to fetch latest versions and propagate
  to build.ps1, main.yml, Dockerfiles and go.mod
- build.ps1 now reads versions from external-tool-versions.json
  at runtime instead of hardcoding values

Bug fixes:
- Add --fix-missing to apt-get in tools Dockerfile to survive
  transient Ubuntu mirror sync failures (exit code 100)
- Remove obsolete [Serializable] / SerializationInfo constructor
  from CommandLineException, resolving SYSLIB0051 build warning

Documentation:
- Spelling, grammar and consistency pass across README.md and all docs