Redesign Get Started section: three-column layout with skills, CLI, and stay updated

- Replace sequential steps with three-column grid (skills/CLI/stay updated)
- Skills column (step 1) gets visual prominence with wider column and Recommended badge
- CLI column (step 2) shows install, subcommands, npm link, Beta badge
- Stay updated column (step 3) leads with Substack embed + X follow, quick refs below
- Add "Best together" callout matching detection-callout pattern
- Unify font sizes and spacing across all columns
- Left-align section content to match rest of page
- Remove demo-caption background, section divider on wide viewports
- Fisheye starts on /clarify for balanced top/bottom
- Magazine container gets white background containment on wide viewports
- Spread-flow stays on one line (nowrap)
- Remove demo-caption background from skill-demos.css

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

public/css/workflow.css

@@ -33,6 +33,14 @@
   overflow: hidden;
 }
 
+@media (min-width: 1100px) {
+  .magazine-container {
+    background: white;
+    border-radius: 16px;
+    padding: var(--spacing-lg);
+  }
+}
+
 /* Fisheye command list */
 .fisheye-list {
   position: relative;
@@ -202,7 +210,7 @@
   gap: 6px;
   flex-wrap: nowrap;
   margin-top: var(--spacing-xs);
-  overflow: hidden;
+  white-space: nowrap;
 }
 
 .spread-flow-label {
@@ -320,7 +328,6 @@
   color: var(--color-ash);
   text-align: center;
   padding: var(--spacing-sm) var(--spacing-md);
-  background: var(--color-paper);
 }
 
 /* Fallback demo container inside spread */