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/step75_test.cpp

@@ -0,0 +1,114 @@
+// Step 75 TDD Test: API documentation and surface verification
+//
+// Tests:
+// 1. APIDocGenerator produces valid markdown documentation
+// 2. All major API categories are covered (parser, generator, validator, optimizer, editor, api)
+// 3. Each entry has component name, description, and methods
+// 4. Documentation includes all core components (at least 20)
+// 5. Generated markdown contains expected section headers
+// 6. Pipeline API is documented
+
+#include <iostream>
+#include <string>
+#include <cassert>
+#include "APIDocGenerator.h"
+
+int main() {
+    int passed = 0;
+    int failed = 0;
+    APIDocGenerator docGen;
+
+    // --- Test 1: APIDocGenerator produces valid markdown ---
+    {
+        std::string markdown = docGen.generateMarkdown();
+        assert(!markdown.empty() && "Should produce non-empty markdown");
+        assert(markdown.find("# Whetstone DSL API Reference") != std::string::npos &&
+               "Should have title");
+        assert(markdown.find("##") != std::string::npos &&
+               "Should have section headers");
+
+        std::cout << "Test 1 PASS: APIDocGenerator produces valid markdown" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 2: All major API categories covered ---
+    {
+        bool covered = docGen.verifyCoverage();
+        assert(covered && "All API categories should be covered");
+
+        std::cout << "Test 2 PASS: All major API categories covered" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 3: Each entry has required fields ---
+    {
+        auto entries = docGen.getAPIEntries();
+        for (const auto& e : entries) {
+            assert(!e.component.empty() && "Entry must have component name");
+            assert(!e.category.empty() && "Entry must have category");
+            assert(!e.description.empty() && "Entry must have description");
+            assert(!e.methods.empty() && "Entry must have at least one method");
+        }
+
+        std::cout << "Test 3 PASS: All entries have required fields" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 4: Documentation covers at least 20 components ---
+    {
+        auto entries = docGen.getAPIEntries();
+        assert(entries.size() >= 20 && "Should document at least 20 components");
+
+        std::cout << "Test 4 PASS: Documents " << entries.size() << " components (>= 20)" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 5: Markdown contains expected category sections ---
+    {
+        std::string markdown = docGen.generateMarkdown();
+        assert(markdown.find("## Parser") != std::string::npos && "Should have Parser section");
+        assert(markdown.find("## Generator") != std::string::npos && "Should have Generator section");
+        assert(markdown.find("## Validator") != std::string::npos && "Should have Validator section");
+        assert(markdown.find("## Optimizer") != std::string::npos && "Should have Optimizer section");
+        assert(markdown.find("## Editor") != std::string::npos && "Should have Editor section");
+
+        std::cout << "Test 5 PASS: Markdown contains expected category sections" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 6: Core components are documented ---
+    {
+        auto entries = docGen.getAPIEntries();
+        bool hasPipeline = false, hasTransformEngine = false, hasTreeSitter = false;
+        bool hasStrategyValidator = false, hasIncrementalOpt = false;
+
+        for (const auto& e : entries) {
+            if (e.component == "Pipeline") hasPipeline = true;
+            if (e.component == "TransformEngine") hasTransformEngine = true;
+            if (e.component == "TreeSitterParser") hasTreeSitter = true;
+            if (e.component == "StrategyValidator") hasStrategyValidator = true;
+            if (e.component == "IncrementalOptimizer") hasIncrementalOpt = true;
+        }
+
+        assert(hasPipeline && "Pipeline should be documented");
+        assert(hasTransformEngine && "TransformEngine should be documented");
+        assert(hasTreeSitter && "TreeSitterParser should be documented");
+        assert(hasStrategyValidator && "StrategyValidator should be documented");
+        assert(hasIncrementalOpt && "IncrementalOptimizer should be documented");
+
+        std::cout << "Test 6 PASS: Core components are documented" << std::endl;
+        ++passed;
+    }
+
+    // --- Print generated documentation ---
+    std::cout << "\n--- Generated API Documentation Preview ---\n" << std::endl;
+    std::string markdown = docGen.generateMarkdown();
+    // Print first 1000 chars as preview
+    std::cout << markdown.substr(0, 1000);
+    if (markdown.size() > 1000) std::cout << "\n... (" << markdown.size() << " total chars)\n";
+    std::cout << std::endl;
+
+    // --- Summary ---
+    std::cout << "=== Step 75 Results: " << passed << " passed, " << failed << " failed ===" << std::endl;
+    return failed > 0 ? 1 : 0;
+}