Make the home page's AS name search work (closes #151)

The AS Name Search card on the home page said the search was coming
soon. It now asks the new GET /api/v1/search/as?q=<text>, which
searches the AS list built into asinfo, and lists the matches as links
to their AS pages. The answer holds the query, the number of matches
and the first 50 of them; an empty q answers 400. asinfo.Search now
ignores case, uses strings.Contains instead of its own substring loop,
and returns its matches in AS number order. A number, or AS and a
number, typed into the card still opens that AS's page. The card builds
the list with textContent, since the names come from outside data.

Model: opus-5-5

TODO.md

@@ -33,6 +33,9 @@ tested.
 
 # Completed Steps
 
+- 2026-10-26: the home page's AS name search lists the ASes whose handle or
+  description holds the text, as links to their pages, from the new
+  `/api/v1/search/as`; the search ignores case (closes #151)
 - 2026-10-19: README "HTTP Endpoints" lists every route with what it answers,
   "Database Schema" matches `schema.sql`, and the rest of the README matches the
   code; this file brought up to date (closes #72)