set explicit box-sizing on .tsmb-form input[type=search]

It's funny how there's only a tiny tiny subset of elements where
browsers apply a box-sizing other than content-box by default (basically
only input fields), and the majority of developers crave to apply
this more widely, yet, in the wild I came across a "reset" rule that
explicitly applies `box-sizing: content-box` to `input[type=search]`,
which then breaks our layout.

Author: Krinkle

typesense-minibar.css

@@ -29,6 +29,7 @@
 }
 
 .tsmb-form input[type=search] {
+  box-sizing: border-box;
   -webkit-appearance: none;
   -moz-appearance: none;
   appearance: none;