fix(audit): Free previous values in EntryBuilder setters

- setTable, setSql, setBefore, setAfter now free old value before setting new
- Prevents memory leak if setter is called multiple times on same builder

src/audit/entry.zig

@@ -357,6 +357,8 @@ pub const EntryBuilder = struct {
     }
 
     pub fn setTable(self: *Self, table: []const u8) !*Self {
+        // Liberar valor anterior si existe (evitar leak si se llama 2 veces)
+        if (self.table) |t| self.allocator.free(t);
         self.table = try self.allocator.dupe(u8, table);
         return self;
     }
@@ -367,16 +369,22 @@ pub const EntryBuilder = struct {
     }
 
     pub fn setSql(self: *Self, sql: []const u8) !*Self {
+        // Liberar valor anterior si existe
+        if (self.sql) |s| self.allocator.free(s);
         self.sql = try self.allocator.dupe(u8, sql);
         return self;
     }
 
     pub fn setBefore(self: *Self, before: []const u8) !*Self {
+        // Liberar valor anterior si existe
+        if (self.before) |b| self.allocator.free(b);
         self.before = try self.allocator.dupe(u8, before);
         return self;
     }
 
     pub fn setAfter(self: *Self, after: []const u8) !*Self {
+        // Liberar valor anterior si existe
+        if (self.after) |a| self.allocator.free(a);
         self.after = try self.allocator.dupe(u8, after);
         return self;
     }