fix(portal): zero first-child top margin so right column aligns flush

Many FP templates slap mt-3/mt-4 onto their root content div (dashboard,
configurator wizard steps, etc.) which still pushed the right column's
content ~16px below the sidebar's top edge even after pt-3 was zeroed
in e50631c. Scope a margin-top: 0 to .o_fp_portal_main #wrap > .container's
first child — strips whichever utility class the template happens to use
without touching siblings or styles below.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_portal/static/src/scss/fp_portal_sidebar.scss

@@ -162,4 +162,14 @@
     #wrap > .container {
         padding-top: 0;
     }
+
+    // Templates often slap mt-3 / mt-4 onto their root content div for
+    // breathing room from the (now-removed) container pt-3. With pt-3
+    // zeroed AND our shell already padding the page, those bottom-margin
+    // utility classes show up as a stray ~16px offset that makes the
+    // right column top sit lower than the sidebar's top edge. Zero out
+    // the top margin of the container's first child so everything aligns.
+    #wrap > .container > :first-child {
+        margin-top: 0;
+    }
 }