style(design-system): apply typography/spacing/radius tokens to shared/ui component library

Normalized the 18 shared/ui components (button, input, select, badge,
card, section-card, table, dialog, empty-state, form-field, pagination,
toggle, image-field, key-value-editor, locale-tabs, color-picker,
code-editor, skeleton) — these are the reusable primitives consumed
across storefront/builder/backoffice — to use the new
--font-size-*/--font-weight-*/--line-height-* tokens and the
--radius-xs/--radius-full tokens introduced in the previous commit,
replacing one-off literal values (0.875rem, 13px, 999px, 12px, etc.).

Fixes found along the way:
- code-editor.component.scss: focus border/shadow used a hardcoded
  #497671 (the dexar tenant's primary color) instead of
  var(--primary-color) — would not adapt to the lavero/novo tenant
  themes. Now theme-aware.
- section-card.component.scss used raw 16px/18px/14px radius/padding
  instead of the --radius-lg/--space-* tokens the sibling card
  component already used, so cards and section-cards had slightly
  different rounding/padding for no reason. Aligned to the same scale.
- toggle/badge/item-tag: raw 999px pill radius replaced with the new
  --radius-full token.

Deferred: syntax-highlighting colors in code-editor (.cm-*) are
intentional and left untouched; tenant brand colors in the three
theme.scss files are intentional per-tenant palettes, left untouched.

src/app/shared/ui/locale-tabs/locale-tabs.component.scss

@@ -9,13 +9,13 @@
 }
 
 .app-locale-tab {
-  padding: 8px 16px;
+  padding: var(--space-sm, 0.5rem) var(--space-md, 1rem);
   border: none;
   border-bottom: 2px solid transparent;
   background: transparent;
   color: var(--text-secondary, #5f6e6a);
-  font-weight: 600;
-  font-size: 0.875rem;
+  font-weight: var(--font-weight-semibold, 600);
+  font-size: var(--font-size-base, 0.875rem);
   text-transform: uppercase;
   cursor: pointer;
   transition: color var(--transition-fast, 120ms ease),