landing: default the install widget to the brew tab

cargo as the default predates brew/npx/curl going live — it forces
the lowest-friction-on-paper option to be a 30-second compile that
needs a Rust toolchain. Brew matches the README ordering and is the
typical dev/ops install path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 7schmiede

landing/index.html

@@ -472,9 +472,9 @@ <h2>Quick start</h2>
       <div class="install-tabs">
         <div class="tab-bar" role="tablist">
           <button class="tab-btn" role="tab" data-tab="codespaces">codespaces</button>
-          <button class="tab-btn" role="tab" data-tab="brew">brew</button>
+          <button class="tab-btn active" role="tab" data-tab="brew">brew</button>
           <button class="tab-btn" role="tab" data-tab="npx">npx</button>
-          <button class="tab-btn active" role="tab" data-tab="cargo">cargo</button>
+          <button class="tab-btn" role="tab" data-tab="cargo">cargo</button>
           <button class="tab-btn" role="tab" data-tab="curl">curl</button>
           <button class="tab-btn" role="tab" data-tab="docker">docker</button>
         </div>
@@ -497,7 +497,7 @@ <h2>Quick start</h2>
         </div>
 
         <!-- brew -->
-        <div class="tab-panel" id="tab-brew" role="tabpanel">
+        <div class="tab-panel active" id="tab-brew" role="tabpanel">
           <div class="tab-panel-header">
             <span>macOS · Linux</span>
           </div>
@@ -531,7 +531,7 @@ <h2>Quick start</h2>
         </div>
 
         <!-- cargo -->
-        <div class="tab-panel active" id="tab-cargo" role="tabpanel">
+        <div class="tab-panel" id="tab-cargo" role="tabpanel">
           <div class="tab-panel-header">
             <span>Rust toolchain required</span>
           </div>