fix(buttons): use inline-flex on all buttons so <a> and <button> render same height

<a> tags are display:inline by default and don't respect vertical padding,
while <button> is inline-block. Mixed anchor/button pairs (View/Add) rendered
at different heights despite identical padding. Apply display:inline-flex +
align-items:center to every button-styled element across SchoolRow, RankingsView,
and SchoolCard. Add border:1px solid transparent to borderless buttons so total
box size matches bordered siblings.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nextjs-app/components/SchoolCard.module.css

@@ -148,15 +148,18 @@
 .btnSecondary,
 .btnPrimary {
   flex: 1;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
   padding: 0.5rem 1rem;
   font-size: 0.875rem;
   font-weight: 600;
   border-radius: 6px;
-  border: none;
+  border: 1px solid transparent;
   cursor: pointer;
-  text-align: center;
   text-decoration: none;
   transition: all 0.2s ease;
+  box-sizing: border-box;
 }
 
 .btnSecondary {
@@ -190,14 +193,17 @@
 
 .btnRemove {
   flex: 1;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
   padding: 0.5rem 1rem;
   font-size: 0.875rem;
   font-weight: 600;
   border-radius: 6px;
   cursor: pointer;
-  text-align: center;
   text-decoration: none;
   transition: all 0.2s ease;
+  box-sizing: border-box;
   background: var(--bg-secondary, #f3ede4);
   color: var(--text-secondary, #5c564d);
   border: 1px solid var(--border-color, #e0ddd8);