v0.2.1-dev – go install unsupported

This release formally documents and accepts that go install is not supported for vultool due to Go module security rules.

• Replace directives - are main-module-only by design, making go install impossible with current upstream dependencies
• Reverted to original mobile-tss-lib with minimal replace directives for reliable local builds
• Updated README- with clear git clone + build instructions
• Added explanation of why go install fails, to help future developers
• Retained all architectural learnings from the go install exploration for future reference

Outcome:

• Local build process remains stable across Linux, macOS, and Windows
• Developers have clear, honest installation steps
• Documentation now includes the "why" behind the limitation