House rules: numbers through one formatter, no made-up server errors, and the rules fail the build

- Every number shown on a page goes through NumbersExtensions: counts,
  percentages, the nerd readouts and the values written into a style.
- A failure the client builds itself (offline, timeout, retries run out, an
  answer it can't read) is a 400 that names its kind; only a server's own 5XX
  passes through.
- Login, sign-up, recovery and password confirmations leave autocomplete to
  the browser, so it can offer the saved login.
- The Daisy components start with empty lists and attributes, and a
  decorative image still renders alt="".
- Arasaka.HouseRules.Analyzers checks all of this in every build, together
  with PrivaPub.ClientModels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W4YtEJrgxG12Pc39Fai8Bd

Pages/Index.razor

@@ -692,7 +692,7 @@
 		if (RequestStats.Latest(1).FirstOrDefault() is { } last)
 		{
 			yield return NerdRow.Of(Localizer["last request"], $"{last.Method} {last.Route}");
-			yield return NerdRow.Of(Localizer["answer"], $"{last.Status} · {last.DurationMs:0} ms · {NerdRow.Bytes(last.Bytes) ?? "?"}");
+			yield return NerdRow.Of(Localizer["answer"], $"{last.Status} · {last.DurationMs.ToDefaultCount()} ms · {NerdRow.Bytes(last.Bytes) ?? "?"}");
 			yield return NerdRow.Of("X-RateLimit-Remaining", last.RateLimitRemaining);
 		}
 	}