Merge S10 (a1): public ledger profiles v1

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

# Conflicts:
#	BUILD-STATE.md
#	CLAUDE.md

web/src/lib/routes.js

@@ -54,6 +54,11 @@ const OPEN_ROUTES = [
   '/welcome',
   '/offline',
   '/upgrade',
+  /* A1 Session 10 — public ledger profiles. /u/:handle is the SHARE surface:
+     it must load anonymous (the whole point is a public record). Publishing
+     is the owner's explicit opt-in; the privacy gate lives in the API
+     (unpublished → 404), never in the router. */
+  '/u',
 ];
 
 /* Hash deep-link aliases (§C.3.4). The prototype was a single HTML file using