refactor: Move config test mode check before directory verification

Relocate the config test mode validation to execute immediately after
configuration parsing succeeds, before any filesystem operations. This
provides faster feedback when using --config-test flag and follows the
fail-fast principle.

Author: libraz

src/main.cpp

@@ -189,6 +189,22 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
+  // Config test mode: validate and exit
+  if (config_test_mode) {
+    std::cout << "Configuration file syntax is OK\n";
+    std::cout << "Configuration details:\n";
+    std::cout << "  MySQL: " << config.mysql.user << "@" << config.mysql.host << ":" << config.mysql.port << "\n";
+    std::cout << "  Tables: " << config.tables.size() << "\n";
+    for (const auto& table : config.tables) {
+      std::cout << "    - " << table.name << " (primary_key: " << table.primary_key
+                << ", ngram_size: " << table.ngram_size << ")\n";
+    }
+    std::cout << "  API TCP: " << config.api.tcp.bind << ":" << config.api.tcp.port << "\n";
+    std::cout << "  Replication: " << (config.replication.enable ? "enabled" : "disabled") << "\n";
+    std::cout << "  Logging level: " << config.logging.level << "\n";
+    return 0;
+  }
+
   // Verify dump directory permissions
   try {
     std::filesystem::path dump_dir(config.dump.dir);
@@ -216,22 +232,6 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
-  // Config test mode: validate and exit
-  if (config_test_mode) {
-    std::cout << "Configuration file syntax is OK\n";
-    std::cout << "Configuration details:\n";
-    std::cout << "  MySQL: " << config.mysql.user << "@" << config.mysql.host << ":" << config.mysql.port << "\n";
-    std::cout << "  Tables: " << config.tables.size() << "\n";
-    for (const auto& table : config.tables) {
-      std::cout << "    - " << table.name << " (primary_key: " << table.primary_key
-                << ", ngram_size: " << table.ngram_size << ")\n";
-    }
-    std::cout << "  API TCP: " << config.api.tcp.bind << ":" << config.api.tcp.port << "\n";
-    std::cout << "  Replication: " << (config.replication.enable ? "enabled" : "disabled") << "\n";
-    std::cout << "  Logging level: " << config.logging.level << "\n";
-    return 0;
-  }
-
   // Initialize table contexts for all configured tables
   spdlog::info("Initializing {} table(s)...", config.tables.size());
   std::unordered_map<std::string, std::unique_ptr<TableContext>> table_contexts;