Complete Harbour-compatible MEMVAR implementation:
- PUBLIC: global scope, persist until program end
- PRIVATE: function scope + called functions, auto-release on return
- Shadowing: PRIVATE can shadow PUBLIC, restored on scope exit
- Nested: multi-level PRIVATE scoping with save/restore stack
- Thread.PushMemvar/PopMemvar: stack-based memvar access
- Thread.DeclarePublic/DeclarePrivate: declaration helpers
- MacroEval: &cVar now looks up memvars (was returning string)
- Shutdown: Phase 4 clears all memvars on all threads
- Case-insensitive: all lookups uppercased
Tests: 12 tests including:
PUBLIC create/update, case-insensitive, PRIVATE basic,
shadow/restore, nested 3-level shadow, new var cleanup,
release, releaseAll, names, thread integration, macro access
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
