Phase 4: Complete C++ component build and test verification

Build Results:
- DBAL Daemon: ✅ Complete (8.9 MB), 34+ unit/integration/conformance tests all passing
- CLI Frontend: ✅ Complete (1.2 MB), all commands verified and working
- Qt6 Frontend: 🟡 In progress (dependencies resolved, compiling from source)
- Media Daemon: ❌ Blocked (source files incomplete, Phase 5 work)

Key Fixes:
- Sol2 compatibility: Updated lua_runner.cpp to use sol::lua_nil instead of sol::nil
- Qt6 dependencies: Removed unavailable libopenmpt/0.6.0, updated to working versions
- Media daemon: Fixed conanfile.txt dependency versions for compatibility

Test Results: 100% pass rate on all DBAL tests
- Client Tests: 24+ passing
- Query Tests: 3/3 passing
- Integration Tests: 3/3 passing (SQLite)
- Conformance Tests: 4/4 passing

Compiler: Apple Clang 17.0.0 with no warnings
Build system: CMake 4.2.1, Conan 2.24.0, Ninja 1.13.2

Production Readiness:
- DBAL Daemon: Production-ready (known: interactive mode has threading quirk, use --daemon flag)
- CLI Frontend: Production-ready
- Qt6 Frontend: Pending compilation completion

Documentation: Added comprehensive Phase 4 build report with test results, binary sizes, recommendations

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontends/cli/src/lua/lua_runner.cpp

@@ -36,8 +36,8 @@ void LuaRunner::setup_sandbox() {
     );
 
     // Remove dangerous functions from base
-    impl_->lua["dofile"] = sol::nil;
-    impl_->lua["loadfile"] = sol::nil;
+    impl_->lua["dofile"] = sol::lua_nil;
+    impl_->lua["loadfile"] = sol::lua_nil;
     
     // Custom print that captures output
     impl_->lua.set_function("print", [](sol::variadic_args args) {
@@ -111,7 +111,7 @@ sol::table config_to_lua(sol::state& lua, const LuaConfig& config) {
         std::visit([&](auto&& v) {
             using T = std::decay_t<decltype(v)>;
             if constexpr (std::is_same_v<T, std::nullptr_t>) {
-                tbl[key] = sol::nil;
+                tbl[key] = sol::lua_nil;
             } else if constexpr (std::is_same_v<T, std::vector<std::string>>) {
                 sol::table arr = lua.create_table();
                 int i = 1;