Unify form styling across invoice, estimate, and recurring invoice pages

Apply consistent rounded-xl shadow border-line-light to customer
selector, date/number fields card, items table, totals card, editor,
tax popup, and view page sidebars. Wrap right-side basic fields in
card container matching the customer card.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

resources/scripts/admin/views/estimates/View.vue

@@ -266,7 +266,7 @@
         class="
           flex-1
           border border-gray-400 border-solid
-          rounded-md
+          rounded-xl
           bg-surface
           frame-style
         "