p2 layout

- _tokens.scss — added --wg-space-2xs…xl (0.25–2rem, 4pt scale), --wg-ledger-line: 1.78rem, --wg-page-width: 1420px.
- Card gaps unified to --wg-space-sm, card interiors to --wg-space-md, the compact topic-list header to --wg-space-xs (_categories.scss, _topics.scss, _widgets.scss, _responsive.scss).
- Ledger ruling height is now one token across topics, posts, pagination, quick-reply, and the composer (_posts.scss, _controls.scss).
- Footer rails now share the topbar's 1420px measure (_footer.scss:36,123,143), so the page's top and bottom edges align.
- Stat tiles got explicit padding instead of inheriting Bootstrap's (_topics.scss:369, _categories.scss:326).
- Documented the scale and rules in DESIGN.md (new "Spacing & Layout" section).

scss/westgate/_footer.scss

@@ -33,7 +33,7 @@
 	display: grid;
 	grid-template-columns: minmax(0, 1.6fr) minmax(10rem, 1fr) minmax(10rem, 1fr);
 	gap: clamp(2rem, 5vw, 3.125rem);
-	width: min(100%, 1240px);
+	width: min(100%, var(--wg-page-width));
 	margin: 0 auto;
 	padding: clamp(2.75rem, 6vw, 4rem) clamp(1rem, 4vw, 2rem) 1.875rem;
 }
@@ -120,7 +120,7 @@
 	justify-content: space-between;
 	flex-wrap: wrap;
 	gap: 0.75rem;
-	width: min(100%, 1240px);
+	width: min(100%, var(--wg-page-width));
 	margin: 0 auto;
 	padding: 1.375rem clamp(1rem, 4vw, 2rem);
 	border-top: 1px solid rgba(194, 163, 90, 0.1);
@@ -140,7 +140,7 @@
 	justify-content: center;
 	flex-wrap: wrap;
 	gap: 0.625rem;
-	width: min(100%, 1240px);
+	width: min(100%, var(--wg-page-width));
 	margin: 0 auto;
 	padding: 0 1rem 1.875rem;
 	font-family: var(--wg-font-ui);