Make the background seals a little stronger in light mode

A --gk-ghost token scales the faint edge seals, panel seals and banners:
1 in dark, 1.6 in light, so their lines read on Starlight.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aSbo2D1qP8cMFQCykf7kx

services/site/src/components/blog/LeadPost.astro

@@ -105,7 +105,7 @@ const now = nowStatuses(s, post);
     position: absolute;
     width: 150%;
     max-width: none;
-    opacity: 0.32;
+    opacity: calc(0.32 * var(--gk-ghost));
     pointer-events: none;
   }
   .art :global(.path) {

services/site/src/components/blog/SidePanel.astro

@@ -37,7 +37,7 @@ const { title, seal, as: H = "h2" } = Astro.props;
     position: absolute;
     right: -26px;
     top: -26px;
-    opacity: 0.14;
+    opacity: calc(0.14 * var(--gk-ghost));
     pointer-events: none;
   }
   .head {

services/site/src/components/work/FeaturedStudy.astro

@@ -92,7 +92,7 @@ const facts = d.facts ?? [];
     position: absolute;
     right: -60px;
     bottom: -80px;
-    opacity: 0.12;
+    opacity: calc(0.12 * var(--gk-ghost));
     pointer-events: none;
   }
   .main {

services/site/src/pages/index.astro

@@ -227,7 +227,7 @@ const listFormat = new Intl.ListFormat("en", { style: "long", type: "conjunction
     position: absolute;
     right: -90px;
     top: -90px;
-    opacity: 0.14;
+    opacity: calc(0.14 * var(--gk-ghost));
     pointer-events: none;
   }
   .work > :not(:global(.work-seal), :global(.gk-corner)) {

services/site/src/pages/now.astro

@@ -209,7 +209,7 @@ const wrapped = s
     top: -26px;
     width: 104px;
     height: 104px;
-    opacity: 0.14;
+    opacity: calc(0.14 * var(--gk-ghost));
     pointer-events: none;
   }
   .panel-kicker {

services/site/src/pages/resume.astro

@@ -402,7 +402,7 @@ const isCore = (group: { core?: string[] }, item: string) => group.core?.some((c
     position: absolute;
     right: -30px;
     top: -30px;
-    opacity: 0.12;
+    opacity: calc(0.12 * var(--gk-ghost));
     pointer-events: none;
   }
   .panel-head {

services/site/src/pages/store/index.astro

@@ -328,7 +328,7 @@ const colorStrips = selling.flatMap((l) =>
     position: absolute;
     right: -40px;
     bottom: -60px;
-    opacity: 0.08;
+    opacity: calc(0.08 * var(--gk-ghost));
     pointer-events: none;
   }
   summary {