Link roundup posts from Shelf cards and keep long link lists short

Shelf game cards show the post about the game, as Library rows already
do. A make's chip prefers its own build log and says Blog for other
posts. Post chips and Connected pages count the links past the first
few, so a roundup linking a hundred items stays readable.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aSbo2D1qP8cMFQCykf7kx

services/site/src/lib/world.ts

@@ -52,6 +52,12 @@ export function buildLogs(s: SiteIndex, craft: Note<"craft">): Note<"post">[] {
   return s.backlinks(craft, { type: "post" }) as Note<"post">[];
 }
 
+/** The post a make links to: its own build log first, else the newest post about it. */
+export function makeLog(s: SiteIndex, make: Note<"make">): Note<"post"> | undefined {
+  const posts = s.backlinks(make, { type: "post" }) as Note<"post">[];
+  return posts.find((p) => p.data.postType === "build log") ?? posts[0];
+}
+
 /** The tools of a craft, as notes where published, in the craft's order. */
 export function toolsOf(s: SiteIndex, craft: Note<"craft">): { title: string; note?: Note<"tool"> }[] {
   return (craft.data.tools ?? []).map((t) => {