adding vec0 module

Author: trvon

include/sqlite-vec-cpp/sqlite/registration.hpp

@@ -6,15 +6,22 @@
 #include "enhanced_functions.hpp"
 #include "functions.hpp"
 #include "utility_functions.hpp"
+#include "vec0_module.hpp"
 
 namespace sqlite_vec_cpp::sqlite {
 
-/// Register all vector distance functions with SQLite
+/// Register all vector distance functions and vec0 virtual table module with SQLite
 inline Result<void> register_all_functions(sqlite3* db) {
     if (!db) {
         return err<void>(Error::invalid_argument("database handle is null"));
     }
 
+    // Register vec0 virtual table module first (critical for CREATE VIRTUAL TABLE)
+    auto vec0_result = register_vec0_module(db);
+    if (!vec0_result) {
+        return vec0_result;
+    }
+
     // Register core distance functions (compatible with original sqlite-vec)
     int rc =
         sqlite3_create_function_v2(db, "vec_distance_l2", 2, SQLITE_UTF8 | SQLITE_DETERMINISTIC,