diff --git a/editor/src/SemannoSidecar.h b/editor/src/SemannoSidecar.h
new file mode 100644
index 0000000..3a0c77a
--- /dev/null
+++ b/editor/src/SemannoSidecar.h
@@ -0,0 +1,160 @@
+#pragma once
+#include <string>
+#include <vector>
+#include <fstream>
+#include <filesystem>
+#include <algorithm>
+#include "ast/ASTNode.h"
+#include "ast/Module.h"
+#include "SemannoFormat.h"
+
+struct SemannoSidecarSaveResult {
+    bool success = false;
+    std::string path;
+    int annotationCount = 0;
+    std::string error;
+};
+
+struct SemannoSidecarLoadResult {
+    bool success = false;
+    std::vector<SemannoEntry> entries;
+    int count = 0;
+    std::string error;
+};
+
+class SemannoSidecar {
+public:
+    // Generates the path for a .semanno sidecar file.
+    // e.g., /path/to/project/src/file.py -> /path/to/project/.whetstone/src/file.py.semanno
+    static std::filesystem::path getSidecarPath(const std::filesystem::path& workspaceRoot, const std::filesystem::path& filePath) {
+        std::filesystem::path relativePath;
+        if (filePath.is_absolute()) {
+            std::error_code ec;
+            relativePath = std::filesystem::relative(filePath, workspaceRoot, ec);
+            if (ec || relativePath.empty()) {
+                relativePath = filePath.filename();
+            }
+        } else {
+            relativePath = filePath;
+        }
+
+        std::filesystem::path sidecarDir = workspaceRoot / ".whetstone";
+        return sidecarDir / (relativePath.generic_string() + ".semanno");
+    }
+
+    // Saves all semantic annotations from an AST module to a .semanno sidecar file.
+    static SemannoSidecarSaveResult saveSemannoSidecar(const std::string& workspaceRoot, const std::string& filePath, const Module* module) {
+        SemannoSidecarSaveResult result;
+        if (!module) {
+            result.error = "No AST to save";
+            return result;
+        }
+
+        std::vector<std::pair<int, std::string>> entries;
+        collectEntries(module, entries);
+        result.annotationCount = static_cast<int>(entries.size());
+
+        auto path = getSidecarPath(workspaceRoot, filePath);
+        result.path = path.string();
+        if (entries.empty()) {
+            try {
+                std::filesystem::create_directories(path.parent_path());
+                std::ofstream file(path);
+                if (!file.is_open()) {
+                    result.error = "Cannot write to " + path.string();
+                    return result;
+                }
+            } catch (const std::filesystem::filesystem_error& e) {
+                result.error = e.what();
+                return result;
+            }
+            result.success = true;
+            return result;
+        }
+
+        // Sort by line number to ensure a stable format
+        std::sort(entries.begin(), entries.end(), [](const auto& a, const auto& b) {
+            return a.first < b.first;
+        });
+
+        try {
+            std::filesystem::create_directories(path.parent_path());
+
+            std::ofstream file(path);
+            if (!file.is_open()) {
+                result.error = "Cannot write to " + path.string();
+                return result;
+            }
+
+            for (const auto& entry : entries) {
+                file << "L" << entry.first << ": " << entry.second << "\n";
+            }
+            result.success = true;
+            return result;
+        } catch (const std::filesystem::filesystem_error& e) {
+            result.error = e.what();
+            return result;
+        }
+    }
+
+    // Loads semantic annotations from a .semanno sidecar file.
+    static SemannoSidecarLoadResult loadSemannoSidecar(const std::string& workspaceRoot, const std::string& filePath) {
+        SemannoSidecarLoadResult result;
+        auto path = getSidecarPath(workspaceRoot, filePath);
+
+        std::ifstream file(path);
+        if (!file.is_open()) {
+            result.error = "No sidecar file: " + path.string();
+            return result;
+        }
+
+        std::string line;
+        while (std::getline(file, line)) {
+            if (line.empty() || line[0] != 'L') continue;
+
+            auto semanno = SemannoParser::parse(line);
+            if (!semanno.type.empty()) {
+                result.entries.push_back(semanno);
+            }
+        }
+        result.count = static_cast<int>(result.entries.size());
+        result.success = true;
+        return result;
+    }
+
+private:
+    // Helper to recursively traverse the AST and collect annotation entries.
+    static void collectEntries(const ASTNode* node, std::vector<std::pair<int, std::string>>& entries) {
+        if (!node) return;
+
+        // An annotation's line number is determined by its parent node
+        if (node->parent && node->parent->spanStartLine >= 0) {
+            std::string semannoString = SemannoEmitter::emit(node);
+            if (!semannoString.empty()) {
+                // Link annotation comments to their parent source line in the sidecar.
+                entries.push_back({node->parent->spanStartLine, semannoString});
+            }
+        }
+
+        // Recurse through all children
+        for (const auto* child : node->allChildren()) {
+            collectEntries(child, entries);
+        }
+    }
+};
+
+inline std::string semannoSidecarPath(const std::string& workspaceRoot,
+                                      const std::string& filePath) {
+    return SemannoSidecar::getSidecarPath(workspaceRoot, filePath).string();
+}
+
+inline SemannoSidecarSaveResult saveSemannoSidecar(const std::string& workspaceRoot,
+                                                   const std::string& filePath,
+                                                   const Module* module) {
+    return SemannoSidecar::saveSemannoSidecar(workspaceRoot, filePath, module);
+}
+
+inline SemannoSidecarLoadResult loadSemannoSidecar(const std::string& workspaceRoot,
+                                                   const std::string& filePath) {
+    return SemannoSidecar::loadSemannoSidecar(workspaceRoot, filePath);
+}
diff --git a/editor/src/SidecarPersistence.h b/editor/src/SidecarPersistence.h
index 723c566..3cb7758 100644
--- a/editor/src/SidecarPersistence.h
+++ b/editor/src/SidecarPersistence.h
@@ -7,6 +7,9 @@
 #include "ast/ASTNode.h"
 #include "ast/Serialization.h"
 #include "ast/Annotation.h"
+#include "ASTUtils.h"
+#include "CompactAST.h"
+#include "SemannoSidecar.h"
 #include <nlohmann/json.hpp>
 #include <string>
 #include <vector>
diff --git a/editor/tests/step295_test.cpp b/editor/tests/step295_test.cpp
new file mode 100644
index 0000000..7f13437
--- /dev/null
+++ b/editor/tests/step295_test.cpp
@@ -0,0 +1,305 @@
+// Step 295: Semanno Sidecar Integration (12 tests)
+#include "SemannoSidecar.h"
+#include "SidecarPersistence.h"
+#include "ast/Module.h"
+#include "ast/Function.h"
+#include "ast/Annotation.h"
+#include "EnvironmentSpec.h"
+#include <iostream>
+#include <filesystem>
+#include <fstream>
+
+static int passed = 0, failed = 0;
+#define TEST(name) { std::cout << "  " << #name << "... "; }
+#define PASS() { std::cout << "PASS\n"; ++passed; }
+#define FAIL(msg) { std::cout << "FAIL: " << msg << "\n"; ++failed; }
+#define CHECK(cond, msg) if (!(cond)) { FAIL(msg); return; } else {}
+
+static std::string tmpDir() {
+    auto p = std::filesystem::temp_directory_path() / "whetstone_test_295";
+    std::filesystem::create_directories(p);
+    return p.string();
+}
+
+static void cleanup() {
+    std::filesystem::remove_all(std::filesystem::temp_directory_path() / "whetstone_test_295");
+}
+
+// Helper: create a module with annotations
+static std::unique_ptr<Module> makeAnnotatedModule() {
+    auto mod = std::make_unique<Module>();
+    mod->name = "test_module";
+
+    auto fn = std::make_unique<Function>();
+    fn->name = "compute";
+    fn->spanStartLine = 5;
+
+    auto intent = std::make_unique<IntentAnnotation>();
+    intent->summary = "computes result";
+    intent->category = "pure";
+    fn->addChild("annotations", intent.release());
+
+    auto risk = std::make_unique<RiskAnnotation>();
+    risk->level = "low";
+    risk->reason = "simple math";
+    fn->addChild("annotations", risk.release());
+
+    mod->addChild("functions", fn.release());
+    return mod;
+}
+
+// 1. Sidecar path generation
+void test_sidecar_path() {
+    TEST(sidecar_path);
+    std::string path = semannoSidecarPath("/workspace", "src/main.py");
+    CHECK(path.find(".whetstone") != std::string::npos, "missing .whetstone dir");
+    CHECK(path.find("src/main.py.semanno") != std::string::npos, "wrong extension");
+    PASS();
+}
+
+// 2. Save creates file on disk
+void test_save_creates_file() {
+    TEST(save_creates_file);
+    cleanup();
+    auto mod = makeAnnotatedModule();
+    auto result = saveSemannoSidecar(tmpDir(), "test.py", mod.get());
+    CHECK(result.success, "save failed: " + result.error);
+    CHECK(result.annotationCount == 2, "wrong count: " + std::to_string(result.annotationCount));
+    CHECK(std::filesystem::exists(result.path), "file not created");
+    PASS();
+}
+
+// 3. Save content format (L<line>: @semanno:...)
+void test_save_content_format() {
+    TEST(save_content_format);
+    cleanup();
+    auto mod = makeAnnotatedModule();
+    auto result = saveSemannoSidecar(tmpDir(), "test.py", mod.get());
+    CHECK(result.success, "save failed");
+
+    std::ifstream in(result.path);
+    std::string content((std::istreambuf_iterator<char>(in)),
+                         std::istreambuf_iterator<char>());
+    CHECK(content.find("L5: @semanno:intent") != std::string::npos, "missing L5 intent");
+    CHECK(content.find("L5: @semanno:risk") != std::string::npos, "missing L5 risk");
+    PASS();
+}
+
+// 4. Load roundtrip
+void test_load_roundtrip() {
+    TEST(load_roundtrip);
+    cleanup();
+    auto mod = makeAnnotatedModule();
+    saveSemannoSidecar(tmpDir(), "test.py", mod.get());
+
+    auto loaded = loadSemannoSidecar(tmpDir(), "test.py");
+    CHECK(loaded.success, "load failed: " + loaded.error);
+    CHECK(loaded.count == 2, "wrong count: " + std::to_string(loaded.count));
+    // Verify entries
+    bool hasIntent = false, hasRisk = false;
+    for (const auto& entry : loaded.entries) {
+        if (entry.type == "intent") hasIntent = true;
+        if (entry.type == "risk") hasRisk = true;
+    }
+    CHECK(hasIntent, "missing intent entry");
+    CHECK(hasRisk, "missing risk entry");
+    PASS();
+}
+
+// 5. Load nonexistent file returns error
+void test_load_nonexistent() {
+    TEST(load_nonexistent);
+    cleanup();
+    auto loaded = loadSemannoSidecar(tmpDir(), "nonexistent.py");
+    CHECK(!loaded.success, "should fail");
+    CHECK(loaded.count == 0, "should have 0 entries");
+    PASS();
+}
+
+// 6. Save null AST returns error
+void test_save_null_ast() {
+    TEST(save_null_ast);
+    auto result = saveSemannoSidecar(tmpDir(), "test.py", nullptr);
+    CHECK(!result.success, "should fail");
+    CHECK(result.error.find("No AST") != std::string::npos, "wrong error");
+    PASS();
+}
+
+// 7. Multiple annotation types in sidecar
+void test_multiple_types() {
+    TEST(multiple_types);
+    cleanup();
+    auto mod = std::make_unique<Module>();
+    mod->name = "multi";
+
+    auto fn = std::make_unique<Function>();
+    fn->name = "process";
+    fn->spanStartLine = 10;
+
+    fn->addChild("annotations", new IntentAnnotation());
+    fn->addChild("annotations", new ComplexityAnnotation());
+    auto contract = new ContractAnnotation();
+    contract->preconditions = "x > 0";
+    fn->addChild("annotations", contract);
+    auto tags = new SemanticTagAnnotation();
+    tags->tags = {"io", "network"};
+    fn->addChild("annotations", tags);
+
+    mod->addChild("functions", fn.release());
+
+    auto result = saveSemannoSidecar(tmpDir(), "multi.py", mod.get());
+    CHECK(result.success, "save failed");
+    CHECK(result.annotationCount == 4, "wrong count: " + std::to_string(result.annotationCount));
+
+    auto loaded = loadSemannoSidecar(tmpDir(), "multi.py");
+    CHECK(loaded.count == 4, "loaded wrong count: " + std::to_string(loaded.count));
+    PASS();
+}
+
+// 8. Sidecar alongside .ast.json
+void test_alongside_ast_sidecar() {
+    TEST(alongside_ast_sidecar);
+    cleanup();
+    auto mod = makeAnnotatedModule();
+
+    // Save both types
+    auto semannoResult = saveSemannoSidecar(tmpDir(), "test.py", mod.get());
+    CHECK(semannoResult.success, "semanno save failed");
+
+    // Also save AST sidecar using SidecarPersistence
+    auto astPath = sidecarPath(tmpDir(), "test.py");
+    namespace fs = std::filesystem;
+    fs::create_directories(fs::path(astPath).parent_path());
+    saveSidecarAST(tmpDir(), "test.py", mod.get());
+
+    // Both files should exist in same .whetstone dir
+    CHECK(fs::exists(semannoResult.path), "semanno file missing");
+    CHECK(fs::exists(astPath), "ast file missing");
+    // Both under .whetstone/
+    CHECK(semannoResult.path.find(".whetstone") != std::string::npos, "wrong dir");
+    CHECK(astPath.find(".whetstone") != std::string::npos, "wrong dir");
+    PASS();
+}
+
+// 9. Environment annotations in sidecar
+void test_environment_annotations() {
+    TEST(environment_annotations);
+    cleanup();
+    auto mod = std::make_unique<Module>();
+    mod->name = "env_test";
+
+    auto fn = std::make_unique<Function>();
+    fn->name = "net_call";
+    fn->spanStartLine = 1;
+
+    auto cap = new CapabilityRequirement();
+    cap->capability = "io.net";
+    cap->required = true;
+    fn->addChild("annotations", cap);
+
+    mod->addChild("functions", fn.release());
+
+    auto result = saveSemannoSidecar(tmpDir(), "net.py", mod.get());
+    CHECK(result.success, "save failed");
+    CHECK(result.annotationCount == 1, "wrong count");
+
+    auto loaded = loadSemannoSidecar(tmpDir(), "net.py");
+    CHECK(loaded.count == 1, "loaded wrong count");
+    CHECK(loaded.entries[0].type == "capability", "wrong type");
+    CHECK(loaded.entries[0].properties["capability"] == "io.net", "wrong cap");
+    PASS();
+}
+
+// 10. Overwrite existing sidecar
+void test_overwrite() {
+    TEST(overwrite);
+    cleanup();
+    auto mod1 = makeAnnotatedModule();
+    saveSemannoSidecar(tmpDir(), "test.py", mod1.get());
+
+    // Save again with different content
+    auto mod2 = std::make_unique<Module>();
+    mod2->name = "changed";
+    auto fn = std::make_unique<Function>();
+    fn->name = "new_func";
+    fn->spanStartLine = 1;
+    fn->addChild("annotations", new PureAnnotation());
+    mod2->addChild("functions", fn.release());
+
+    auto result = saveSemannoSidecar(tmpDir(), "test.py", mod2.get());
+    CHECK(result.success, "save failed");
+    // PureAnnotation is Subject 1 memory — check if isSemanticAnnotation includes it
+    // PureAnnotation is from Sprint 3 original set, check what isSemanticAnnotation says
+    // Either way the save should succeed
+    auto loaded = loadSemannoSidecar(tmpDir(), "test.py");
+    CHECK(loaded.success, "load failed");
+    PASS();
+}
+
+// 11. Properties preserved in roundtrip
+void test_properties_preserved() {
+    TEST(properties_preserved);
+    cleanup();
+    auto mod = std::make_unique<Module>();
+    mod->name = "props";
+
+    auto fn = std::make_unique<Function>();
+    fn->name = "f";
+    fn->spanStartLine = 3;
+
+    auto contract = new ContractAnnotation();
+    contract->preconditions = "len(arr) > 0";
+    contract->postconditions = "result >= 0";
+    contract->returnShape = "int";
+    contract->sideEffects = "none";
+    fn->addChild("annotations", contract);
+
+    mod->addChild("functions", fn.release());
+
+    saveSemannoSidecar(tmpDir(), "props.py", mod.get());
+    auto loaded = loadSemannoSidecar(tmpDir(), "props.py");
+    CHECK(loaded.success, "load failed");
+    CHECK(loaded.count == 1, "wrong count");
+
+    auto& entry = loaded.entries[0];
+    CHECK(entry.type == "contract", "wrong type");
+    CHECK(entry.properties["preconditions"] == "len(arr) > 0", "preconditions lost");
+    CHECK(entry.properties["postconditions"] == "result >= 0", "postconditions lost");
+    PASS();
+}
+
+// 12. Empty module produces empty sidecar
+void test_empty_module() {
+    TEST(empty_module);
+    cleanup();
+    auto mod = std::make_unique<Module>();
+    mod->name = "empty";
+
+    auto result = saveSemannoSidecar(tmpDir(), "empty.py", mod.get());
+    CHECK(result.success, "save failed");
+    CHECK(result.annotationCount == 0, "should be empty");
+
+    auto loaded = loadSemannoSidecar(tmpDir(), "empty.py");
+    CHECK(loaded.success, "load failed");
+    CHECK(loaded.count == 0, "should be empty");
+    PASS();
+}
+
+int main() {
+    std::cout << "=== Step 295: Semanno Sidecar Integration Tests ===\n";
+    test_sidecar_path();
+    test_save_creates_file();
+    test_save_content_format();
+    test_load_roundtrip();
+    test_load_nonexistent();
+    test_save_null_ast();
+    test_multiple_types();
+    test_alongside_ast_sidecar();
+    test_environment_annotations();
+    test_overwrite();
+    test_properties_preserved();
+    test_empty_module();
+    cleanup();
+    std::cout << "\nResults: " << passed << "/" << (passed + failed) << " passed\n";
+    return failed > 0 ? 1 : 0;
+}
diff --git a/editor/tests/step296_test.cpp b/editor/tests/step296_test.cpp
new file mode 100644
index 0000000..86a4fe7
--- /dev/null
+++ b/editor/tests/step296_test.cpp
@@ -0,0 +1,336 @@
+// Step 296: Phase 11a Integration Tests (8 tests)
+#include "ast/PythonGenerator.h"
+#include "ast/CppGenerator.h"
+#include "ast/RustGenerator.h"
+#include "ast/GoGenerator.h"
+#include "ast/JavaGenerator.h"
+#include "ast/JavaScriptGenerator.h"
+#include "ast/ElispGenerator.h"
+#include "SemannoFormat.h"
+#include "SemannoSidecar.h"
+#include "ast/Module.h"
+#include "ast/Function.h"
+#include "ast/Annotation.h"
+#include "EnvironmentSpec.h"
+#include <iostream>
+#include <filesystem>
+#include <vector>
+#include <string>
+#include <memory>
+
+static int passed = 0, failed = 0;
+#define TEST(name) { std::cout << "  " << #name << "... "; }
+#define PASS() { std::cout << "PASS\n"; ++passed; }
+#define FAIL(msg) { std::cout << "FAIL: " << msg << "\n"; ++failed; }
+#define CHECK(cond, msg) if (!(cond)) { FAIL(msg); return; } else {}
+
+static std::string tmpDir() {
+    auto p = std::filesystem::temp_directory_path() / "whetstone_test_296";
+    std::filesystem::create_directories(p);
+    return p.string();
+}
+
+static void cleanup() {
+    std::filesystem::remove_all(std::filesystem::temp_directory_path() / "whetstone_test_296");
+}
+
+// 1. Module with Subject 2-8 annotations generates Semanno in all generators
+void test_multi_subject_generation() {
+    TEST(multi_subject_generation);
+    auto mod = std::make_unique<Module>();
+    mod->name = "annotated";
+
+    auto fn = std::make_unique<Function>();
+    fn->name = "process";
+
+    // One from each subject
+    auto bw = new BitWidthAnnotation(); bw->width = 32;           // S2
+    auto atomic = new AtomicAnnotation(); atomic->consistency = "seq_cst";  // S3
+    auto cap = new CaptureAnnotation(); cap->strategy = "move";    // S4
+    auto shim = new ShimAnnotation(); shim->strategy = "vtable";   // S5
+    auto loop = new LoopAnnotation(); loop->hint = "unroll";       // S6
+    auto meta = new MetaAnnotation(); meta->state = "quoted"; meta->phase = "compile"; // S7
+    auto policy = new PolicyAnnotation(); policy->strictness = "high"; // S8
+
+    fn->addChild("annotations", bw);
+    fn->addChild("annotations", atomic);
+    fn->addChild("annotations", cap);
+    fn->addChild("annotations", shim);
+    fn->addChild("annotations", loop);
+    fn->addChild("annotations", meta);
+    fn->addChild("annotations", policy);
+
+    mod->addChild("functions", fn.release());
+
+    PythonGenerator gen;
+    std::string result = gen.generate(mod.get());
+
+    CHECK(result.find("@semanno:bitwidth") != std::string::npos, "missing S2");
+    CHECK(result.find("@semanno:atomic") != std::string::npos, "missing S3");
+    CHECK(result.find("@semanno:capture") != std::string::npos, "missing S4");
+    CHECK(result.find("@semanno:shim") != std::string::npos, "missing S5");
+    CHECK(result.find("@semanno:loop") != std::string::npos, "missing S6");
+    CHECK(result.find("@semanno:meta") != std::string::npos, "missing S7");
+    CHECK(result.find("@semanno:policy") != std::string::npos, "missing S8");
+    PASS();
+}
+
+// 2. Cross-language: annotations preserved through projection (generate same module with diff generators)
+void test_cross_language_preservation() {
+    TEST(cross_language_preservation);
+    auto mod = std::make_unique<Module>();
+    mod->name = "cross";
+    auto fn = std::make_unique<Function>();
+    fn->name = "sort";
+    fn->addChild("annotations", new LoopAnnotation());
+    fn->addChild("annotations", new PureAnnotation());
+    mod->addChild("functions", fn.release());
+
+    PythonGenerator pyGen;
+    CppGenerator cppGen;
+    RustGenerator rsGen;
+
+    std::string py = pyGen.generate(mod.get());
+    std::string cpp = cppGen.generate(mod.get());
+    std::string rs = rsGen.generate(mod.get());
+
+    CHECK(py.find("@semanno:loop") != std::string::npos, "py missing loop");
+    CHECK(cpp.find("@semanno:loop") != std::string::npos, "cpp missing loop");
+    CHECK(rs.find("@semanno:loop") != std::string::npos, "rs missing loop");
+    PASS();
+}
+
+// 3. All 7 generators produce non-empty Semanno for every annotation type (exhaustive)
+void test_exhaustive_no_unknown() {
+    TEST(exhaustive_no_unknown);
+
+    // Create one of each annotation type
+    std::vector<std::unique_ptr<ASTNode>> annotations;
+    // Subject 2
+    { auto a = std::make_unique<BitWidthAnnotation>(); a->width = 8; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<EndianAnnotation>(); a->order = "little"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<LayoutAnnotation>(); a->mode = "aligned"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<NullabilityAnnotation>(); a->nullable = true; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<VarianceAnnotation>(); a->variance = "invariant"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<IdentityAnnotation>(); a->mode = "structural"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<MutAnnotation>(); a->depth = "shallow"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<TypeStateAnnotation>(); a->state = "erased"; annotations.push_back(std::move(a)); }
+    // Subject 3
+    { auto a = std::make_unique<AtomicAnnotation>(); a->consistency = "relaxed"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<SyncAnnotation>(); a->primitive = "spin"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ThreadModelAnnotation>(); a->model = "os"; annotations.push_back(std::move(a)); }
+    { annotations.push_back(std::make_unique<MemoryBarrierAnnotation>()); }
+    { auto a = std::make_unique<ExecAnnotation>(); a->mode = "event"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<BlockingAnnotation>(); a->kind = "compute"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ParallelAnnotation>(); a->kind = "task"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<TrapAnnotation>(); a->signal = "SIGSEGV"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ExceptionAnnotation>(); a->style = "unchecked"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<PanicAnnotation>(); a->behavior = "unwind"; annotations.push_back(std::move(a)); }
+    // Subject 4
+    { auto a = std::make_unique<BindingAnnotation>(); a->time = "dynamic"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<LookupAnnotation>(); a->mode = "hoisted"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<CaptureAnnotation>(); a->strategy = "ref"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<VisibilityAnnotation>(); a->level = "internal"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<NamespaceAnnotation>(); a->style = "flat"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ScopeAnnotation>(); a->kind = "global_leaked"; annotations.push_back(std::move(a)); }
+    // Subject 5
+    { auto a = std::make_unique<IntrinsicAnnotation>(); a->instruction = "nop"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<RawAnnotation>(); a->language = "c"; a->code = "x"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<CallingConvAnnotation>(); a->convention = "fastcall"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<LinkAnnotation>(); a->symbolName = "s"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ShimAnnotation>(); a->strategy = "cast"; annotations.push_back(std::move(a)); }
+    { annotations.push_back(std::make_unique<PointerArithmeticAnnotation>()); }
+    { auto a = std::make_unique<OpaqueAnnotation>(); a->reason = "r"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<TargetAnnotation>(); a->platform = "linux"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<FeatureAnnotation>(); a->flag = "sse2"; a->enabled = true; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<OriginalAnnotation>(); a->sourceCode = "x"; a->sourceLanguage = "py"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<MappingAnnotation>(); a->history = {"a"}; annotations.push_back(std::move(a)); }
+    // Subject 6
+    { annotations.push_back(std::make_unique<TailCallAnnotation>()); }
+    { auto a = std::make_unique<LoopAnnotation>(); a->hint = "vectorize"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<DataAnnotation>(); a->hint = "restrict"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<AlignAnnotation>(); a->bytes = 16; annotations.push_back(std::move(a)); }
+    { annotations.push_back(std::make_unique<PackAnnotation>()); }
+    { auto a = std::make_unique<BoundsCheckAnnotation>(); a->enabled = true; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<OverflowAnnotation>(); a->behavior = "saturation"; annotations.push_back(std::move(a)); }
+    // Subject 7
+    { auto a = std::make_unique<MetaAnnotation>(); a->state = "quoted"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<SymbolAnnotation>(); a->mode = "gensym"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<EvaluateAnnotation>(); a->phase = "compile_time"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<TemplateAnnotation>(); a->specialization = "erasure"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<SyntheticAnnotation>(); a->generator = "macro"; annotations.push_back(std::move(a)); }
+    // Subject 8
+    { auto a = std::make_unique<PolicyAnnotation>(); a->strictness = "low"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<AmbiguityAnnotation>(); a->intent = "x"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<CandidateAnnotation>(); a->inferredTypes = {"int"}; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<TradeoffAnnotation>(); a->reason = "r"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ChoiceAnnotation>(); a->choiceId = "c"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<DecisionAnnotation>(); a->choiceId = "c"; a->selection = "a"; annotations.push_back(std::move(a)); }
+    // Semantic Core
+    { auto a = std::make_unique<IntentAnnotation>(); a->summary = "s"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ComplexityAnnotation>(); a->timeComplexity = "O(1)"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<RiskAnnotation>(); a->level = "low"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<ContractAnnotation>(); a->preconditions = "x"; annotations.push_back(std::move(a)); }
+    { auto a = std::make_unique<SemanticTagAnnotation>(); a->tags = {"io"}; annotations.push_back(std::move(a)); }
+    // Environment
+    { auto a = std::make_unique<CapabilityRequirement>(); a->capability = "gc"; a->required = true; annotations.push_back(std::move(a)); }
+
+    PythonGenerator py;
+    CppGenerator cpp;
+    int unknownCount = 0;
+    for (const auto& a : annotations) {
+        std::string pyRes = py.generate(a.get());
+        std::string cppRes = cpp.generate(a.get());
+        if (pyRes.find("Unknown") != std::string::npos) {
+            std::cout << "Python Unknown: " << a->conceptType << "\n";
+            ++unknownCount;
+        }
+        if (cppRes.find("Unknown") != std::string::npos) {
+            std::cout << "C++ Unknown: " << a->conceptType << "\n";
+            ++unknownCount;
+        }
+    }
+    CHECK(unknownCount == 0, std::to_string(unknownCount) + " Unknown results");
+    CHECK(annotations.size() >= 56, "expected 56+ types, got " + std::to_string(annotations.size()));
+    PASS();
+}
+
+// 4. Semanno roundtrip: generate → parse back → match
+void test_semanno_roundtrip() {
+    TEST(semanno_roundtrip);
+    CppGenerator gen;
+
+    auto anno = std::make_unique<PolicyAnnotation>();
+    anno->strictness = "high";
+    anno->perf = "critical";
+    anno->style = "idiomatic";
+    anno->binaryStable = false;
+
+    std::string generated = gen.generate(anno.get());
+    auto entry = SemannoParser::parse(generated);
+    CHECK(entry.type == "policy", "wrong type");
+    CHECK(entry.properties["strictness"] == "high", "strictness lost");
+    CHECK(entry.properties["perf"] == "critical", "perf lost");
+    CHECK(entry.properties["style"] == "idiomatic", "style lost");
+    PASS();
+}
+
+// 5. Mixed legacy + new annotations in single module
+void test_mixed_legacy_new() {
+    TEST(mixed_legacy_new);
+    auto mod = std::make_unique<Module>();
+    mod->name = "mixed";
+    auto fn = std::make_unique<Function>();
+    fn->name = "calc";
+
+    // Legacy (Subject 1 memory)
+    auto reclaim = new ReclaimAnnotation();
+    reclaim->strategy = "Tracing";
+    fn->addChild("annotations", reclaim);
+
+    // New (Subject 6)
+    auto loop = new LoopAnnotation();
+    loop->hint = "vectorize";
+    fn->addChild("annotations", loop);
+
+    // Semantic core
+    auto intent = new IntentAnnotation();
+    intent->summary = "calculates sum";
+    fn->addChild("annotations", intent);
+
+    mod->addChild("functions", fn.release());
+
+    CppGenerator gen;
+    std::string result = gen.generate(mod.get());
+    // Legacy memory annotations may use their own format (not semanno)
+    // New annotations should use semanno
+    CHECK(result.find("@semanno:loop") != std::string::npos, "missing loop");
+    CHECK(result.find("@semanno:intent") != std::string::npos, "missing intent");
+    PASS();
+}
+
+// 6. Semanno sidecar roundtrip with all subjects
+void test_sidecar_all_subjects() {
+    TEST(sidecar_all_subjects);
+    cleanup();
+    auto mod = std::make_unique<Module>();
+    mod->name = "sidecar_test";
+    auto fn = std::make_unique<Function>();
+    fn->name = "f";
+    fn->spanStartLine = 1;
+
+    fn->addChild("annotations", new IntentAnnotation());
+    auto bw = new BitWidthAnnotation(); bw->width = 32;
+    fn->addChild("annotations", bw);
+    auto atomic = new AtomicAnnotation(); atomic->consistency = "seq_cst";
+    fn->addChild("annotations", atomic);
+
+    mod->addChild("functions", fn.release());
+
+    auto saved = saveSemannoSidecar(tmpDir(), "all.py", mod.get());
+    CHECK(saved.success, "save failed");
+    CHECK(saved.annotationCount == 3, "wrong save count: " + std::to_string(saved.annotationCount));
+
+    auto loaded = loadSemannoSidecar(tmpDir(), "all.py");
+    CHECK(loaded.success, "load failed");
+    CHECK(loaded.count == 3, "wrong load count: " + std::to_string(loaded.count));
+    PASS();
+}
+
+// 7. Generator comment prefix matches language convention
+void test_all_prefixes() {
+    TEST(all_prefixes);
+    PythonGenerator py;
+    CppGenerator cpp;
+    RustGenerator rs;
+    GoGenerator go;
+    JavaGenerator java;
+    JavaScriptGenerator js;
+    ElispGenerator elisp;
+
+    CHECK(py.commentPrefix() == "# ", "py");
+    CHECK(cpp.commentPrefix() == "// ", "cpp");
+    CHECK(rs.commentPrefix() == "// ", "rs");
+    CHECK(go.commentPrefix() == "// ", "go");
+    CHECK(java.commentPrefix() == "// ", "java");
+    CHECK(js.commentPrefix() == "// ", "js");
+    CHECK(elisp.commentPrefix() == ";; ", "elisp");
+    PASS();
+}
+
+// 8. Marker annotations produce correct Semanno (no parentheses)
+void test_marker_semanno() {
+    TEST(marker_semanno);
+    CppGenerator gen;
+
+    auto pure = std::make_unique<PureAnnotation>();
+    auto tailcall = std::make_unique<TailCallAnnotation>();
+    auto pack = std::make_unique<PackAnnotation>();
+    auto barrier = std::make_unique<MemoryBarrierAnnotation>();
+    auto ptrArith = std::make_unique<PointerArithmeticAnnotation>();
+
+    std::string pureResult = gen.generate(pure.get());
+    std::string tailResult = gen.generate(tailcall.get());
+    std::string packResult = gen.generate(pack.get());
+
+    // Marker annotations should NOT have parentheses
+    CHECK(pureResult.find("(") == std::string::npos, "pure has parens: " + pureResult);
+    CHECK(tailResult.find("(") == std::string::npos, "tailcall has parens: " + tailResult);
+    CHECK(packResult.find("(") == std::string::npos, "pack has parens: " + packResult);
+    PASS();
+}
+
+int main() {
+    std::cout << "=== Step 296: Phase 11a Integration Tests ===\n";
+    test_multi_subject_generation();
+    test_cross_language_preservation();
+    test_exhaustive_no_unknown();
+    test_semanno_roundtrip();
+    test_mixed_legacy_new();
+    test_sidecar_all_subjects();
+    test_all_prefixes();
+    test_marker_semanno();
+    cleanup();
+    std::cout << "\nResults: " << passed << "/" << (passed + failed) << " passed\n";
+    return failed > 0 ? 1 : 0;
+}
diff --git a/progress.md b/progress.md
index 666593a..a73502b 100644
--- a/progress.md
+++ b/progress.md
@@ -843,3 +843,40 @@ generators. Prefix verification, annotation output, exhaustive no-Unknown check.
   and `SemannoAnnotationImpl : public virtual AnnotationVisitorExtended` to resolve
   diamond inheritance ambiguity in generator classes
 - Removed circular include: `EnvironmentSpec.h` no longer includes `ast/Serialization.h`
+
+### Step 295: Semanno Sidecar Integration (12 tests)
+**Status:** PASS (12/12 tests)
+
+Semanno sidecar persistence now supports full save/load roundtrip behavior,
+including empty sidecar file handling.
+
+**Key files:**
+- `editor/src/SemannoSidecar.h` — implemented sidecar API with structured
+  save/load results, path helper, line-keyed `L<line>: @semanno:...` emission,
+  and empty-module sidecar creation.
+- `editor/src/SidecarPersistence.h` — include fixes for AST helper symbols used
+  by sidecar merge logic.
+- `editor/tests/step295_test.cpp` — includes sidecar persistence integration
+  checks alongside Semanno sidecar tests.
+
+### Step 296: Phase 11a Integration Tests (8 tests)
+**Status:** PASS (8/8 tests)
+
+Full Phase 11a integration validation now passes end-to-end.
+
+**Key files:**
+- `editor/src/SemannoSidecar.h` — added result-based free-function API used by
+  Sprint 11 tests (`semannoSidecarPath`, `saveSemannoSidecar`,
+  `loadSemannoSidecar`), path/error/count reporting, and corrected line mapping
+  to use parent `spanStartLine`.
+- `editor/tests/step296_test.cpp` — integration suite executed and passing.
+
+**Verified checks:**
+- Parse/annotate/generate path preserves Subject 2-8 Semanno output.
+- Cross-language generators preserve Semanno annotations.
+- Exhaustive no-Unknown emission for 56+ annotation types.
+- Semanno parse roundtrip for structured properties.
+- Mixed legacy + new annotation handling in one module.
+- Semanno sidecar save/load integration with expected counts.
+- Language comment prefix conventions.
+- Marker annotation emission without property parentheses.