fix(landing): sp-grid 6 columns, shorten Pi card text

- grid-template-columns: 5 → 6 so all adapters fit one row on desktop
  (Shell was wrapping to a lonely second row)
- Pi card org: "OpenRouter / Anthropic / OpenAI / Gemini" → "Multi-provider"
  to match OpenCode's single-line style at narrower 1/6 width

Author: oxgeneral

landing/index.html

@@ -502,7 +502,7 @@
 
     .sp-grid {
       display: grid;
-      grid-template-columns: repeat(5, 1fr);
+      grid-template-columns: repeat(6, 1fr);
       gap: 1px;
       background: var(--gray-light);
     }
@@ -2393,7 +2393,7 @@ <h1>Run multiple AI agents. <em>Without babysitting any of them.</em></h1>
         </div>
         <div class="sp-card">
           <div class="sp-card-name">Pi</div>
-          <div class="sp-card-org">OpenRouter / Anthropic / OpenAI / Gemini</div>
+          <div class="sp-card-org">Multi-provider</div>
           <span class="sp-card-badge native">native</span>
         </div>
         <div class="sp-card">