Steps 290-294: Phase 11a — Semanno format, annotation codegen, visitor dispatch (60/60 tests)

Semanno comment format standard (@semanno:type(key=value)) with emitter/parser
covering all 67+ annotation types. SemannoAnnotationImpl CRTP mixin provides
default visitor implementations for all 56 extended annotation methods across
7 language generators. Virtual inheritance resolves diamond ambiguity between
ProjectionGenerator and SemannoAnnotationImpl.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

editor/src/AnnotationConflict.h

@@ -71,3 +71,5 @@ inline void collectAnnotationConflicts(const ASTNode* node,
         collectAnnotationConflicts(child, out);
     }
 }
+
+#include "AnnotationConflictExtended.h"