feat(project): add strict native TOML parsing

Author: GaspardKirira

CMakeLists.txt

@@ -74,6 +74,9 @@ add_executable(vix::cli ALIAS vix_cli)
 target_include_directories(vix_cli PRIVATE
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
 )
+target_include_directories(vix_cli SYSTEM PRIVATE
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/third_party/tomlplusplus>
+)
 
 function(vix_add_flag_if_supported tgt flag)
   string(REGEX REPLACE "[^A-Za-z0-9]" "_" flag_var "${flag}")

include/vix/cli/project/native/TomlParser.hpp

@@ -0,0 +1,64 @@
+/** @file TomlParser.hpp
+ *  Strict TOML format-1 readers for native project/package artifacts.
+ *  This interface intentionally contains no third-party TOML types.
+ */
+#ifndef VIX_CLI_PROJECT_NATIVE_TOML_PARSER_HPP
+#define VIX_CLI_PROJECT_NATIVE_TOML_PARSER_HPP
+
+#include <filesystem>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include <vix/cli/project/native/Models.hpp>
+#include <vix/cli/project/native/Validation.hpp>
+
+namespace vix::cli::project::native
+{
+  enum class ParseErrorCode
+  {
+    toml_syntax_error,
+    unsupported_format,
+    missing_field,
+    unknown_field,
+    wrong_type,
+    invalid_value,
+    invalid_discriminated_shape,
+    io_error
+  };
+
+  struct ParseIssue
+  {
+    ParseErrorCode code{ParseErrorCode::invalid_value};
+    std::string fieldPath;
+    std::string message;
+    std::optional<ValidationLocation> location;
+  };
+
+  template <typename T>
+  struct ParseResult
+  {
+    std::optional<T> value;
+    std::vector<ParseIssue> issues;
+    [[nodiscard]] bool valid() const noexcept { return value.has_value() && issues.empty(); }
+  };
+
+  [[nodiscard]] ParseResult<NativeProject> parse_native_manifest_text(
+      std::string_view text, std::string_view source = "<text>");
+  [[nodiscard]] ParseResult<NativeProject> parse_native_manifest_file(const std::filesystem::path &path);
+
+  [[nodiscard]] ParseResult<PackageContract> parse_package_contract_text(
+      std::string_view text, std::string_view source = "<text>");
+  [[nodiscard]] ParseResult<PackageContract> parse_package_contract_file(const std::filesystem::path &path);
+
+  [[nodiscard]] ParseResult<Lockfile> parse_lockfile_text(
+      std::string_view text, std::string_view source = "<text>");
+  [[nodiscard]] ParseResult<Lockfile> parse_lockfile_file(const std::filesystem::path &path);
+
+  // Semantic validation remains explicit and is performed by the P10A APIs:
+  // validate_native_project, validate_package_contract, and validate_lockfile.
+  [[nodiscard]] std::string_view to_string(ParseErrorCode code) noexcept;
+} // namespace vix::cli::project::native
+
+#endif // VIX_CLI_PROJECT_NATIVE_TOML_PARSER_HPP