add chain family dl (#3310)

Author: khadni

src/components/HeadCommon.astro

@@ -81,6 +81,31 @@ const { title } = Astro.props
   })()
 </script>
 
+<!-- Set CCIP Chain Family in dataLayer -->
+<script is:inline type="text/javascript">
+  ;(function () {
+    if (!window.location.pathname.startsWith("/ccip")) return
+
+    try {
+      var savedChain = localStorage.getItem("chainlink-docs-chain-type")
+      // Default to "evm" if not set or invalid
+      var chainFamily =
+        savedChain === "solana" || savedChain === '"solana"'
+          ? "solana"
+          : savedChain === "aptos" || savedChain === '"aptos"'
+            ? "aptos"
+            : "evm"
+
+      window.dataLayer = window.dataLayer || []
+      window.dataLayer.push({
+        ccip_chain_family: chainFamily,
+      })
+    } catch (e) {
+      // localStorage unavailable, skip tracking
+    }
+  })()
+</script>
+
 <!-- Google Tag Manager (lazy init on first interaction or idle) -->
 <script type="text/javascript">
   ;(function (w, d, s, l, i) {