Sprint 3 complete: Phases 3g+3h (Steps 68-75), all 75 steps done

Phase 3g — Optimization Pipeline (17/17 tests):
  Step 68: TransformEngine — constant folding, dead code elimination, OptimizationLock warning
  Step 69: StrategyAwareOptimizer — annotation-constrained (@Reclaim allows, @Owner blocks duplication, @Deallocate blocks reorder, @Allocate blocks dynamic)
  Step 70: StrategyValidator — post-optimization invariants (use-after-free, leak, aliasing)
  Step 71: IncrementalOptimizer — transform journal, undo by ID, provenance tracking

Phase 3h — Integration & Validation (26/26 tests):
  Step 72: Pipeline — end-to-end parse→infer→validate→optimize→generate for Python/C++
  Step 73: Error handling — empty ASTs, null roots, nonexistent IDs, unannotated code
  Step 74: Performance benchmarks — 1000-fn AST 1ms, JSON round-trip 4ms, 50 transforms+undo 1ms
  Step 75: APIDocGenerator — structured docs for 23 components across 6 categories

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

editor/tests/step70_test.cpp

@@ -22,19 +22,7 @@
 #include "ast/Expression.h"
 #include "ast/Annotation.h"
 
-// Forward declaration — StrategyValidator
-class StrategyValidator {
-public:
-    struct Violation {
-        std::string severity;   // "error" or "warning"
-        std::string category;   // "use-after-free", "leak", "double-move", "aliasing", "destructor-unreachable"
-        std::string message;
-        std::string nodeId;
-    };
-
-    // Validate all memory strategy invariants
-    std::vector<Violation> validateInvariants(const ASTNode* root) const;
-};
+#include "StrategyValidator.h"
 
 static bool hasViolation(const std::vector<StrategyValidator::Violation>& violations,
                           const std::string& category) {