feat: Add file parsing entry point and refine grammar rules

Signed-off-by: erick-alcachofa <erick@artichoke.dev>

- Updated `main.cpp` to read source files and invoke the parser using
  `MatcherRule<rules::Program>`, providing clear error output or success
  indication.
- Replaced `peek` with `peekExpect` in `Parser` to ensure expected token
  types.
- Replaced parentheses with curly braces for struct and enum definitions
  as specified on grammar.
- Fixed `StructMembers` and `EnumMembers` to allow zero or more entries
  as specified on grammar.
- Replaced `MatcherNoneOrOnce` with `MatcherNoneOrMore` in expression
  rules to support chained binary expressions as specified on grammar.
- Reorganized `PrimaryTypeExpression` to include all valid expression
  types, and reordered rules for better match accuracy.
- Fixed `TypesListR` to correctly refer to `Type` instead of
  `TypesListR` in its recursive rule.

These changes fixes language grammar coverage, fix structural parsing
bugs, and enable full file parsing from the frontend.

frontend/src/main.cpp

@@ -1,5 +1,45 @@
 #include <print>
+#include <fstream>
 
-int main(int, char **) {
-  std::println("[LOG] Hello world");
+#include <artichoke/Parser/Parser.hpp>
+
+int main(int argc, char **argv) {
+  using namespace arti::lang;
+
+  if (argc < 2) {
+    std::println("Usage:\n  {} <filename>", argv[0]);
+    return -1;
+  }
+
+  std::ifstream file;
+  file.open(argv[1]);
+
+  if (!file.is_open()) {
+    std::println("Failed to open file {}", argv[1]);
+    return -1;
+  }
+
+  std::string buffer{
+    std::istreambuf_iterator<char>(file),
+    std::istreambuf_iterator<char>()
+  };
+
+  Tokenizer tokenizer{buffer};
+
+  auto result = MatcherRule<rules::Program>::parse(&tokenizer, 0);
+
+  if (!result) {
+    auto err = std::move(result).error();
+    std::println(
+      "Error at line {}, column {}. {}",
+      err.line,
+      err.column,
+      err.message
+    );
+  }
+  else {
+    std::println("Valid source");
+  }
+
+  return 0;
 }

lib/src/Parser/Parser.cpp

@@ -0,0 +1 @@
+#include <artichoke/Parser/Parser.hpp>