refactor: Eliminate intermediate Match struct allocation

[zharinov]

Summary

• Delete intermediate Match struct (with Vec fields) that existed only as allocation overhead
• Rename MatchView → Match - this zero-copy view is now the only Match type
• Inline serialization directly in MatchIR::resolve() instead of going through Match::to_bytes()

Why

The bytecode layer had three redundant representations: MatchIR (compile-time), Match (intermediate with Vecs), and MatchView (runtime). The middle layer existed only to allocate temporary Vecs during resolve() before immediately serializing them. This refactoring eliminates that wasteful allocation path.