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

Components/Nerd/NerdRow.cs

@@ -1,5 +1,7 @@
 using System.Globalization;
 
+using decePubClient.Extensions;
+
 namespace decePubClient.Components.Nerd;
 
 /// <summary>One line of a NerdTip; a row without a value is not shown.</summary>
@@ -9,7 +11,7 @@ public sealed record NerdRow(string Label, string Value)
 	{
 		null => null,
 		DateTime time => Time(time),
-		double number => number.ToString("0.###", CultureInfo.InvariantCulture),
+		double number => number.ToReadout(),
 		bool flag => flag ? "yes" : "no",
 		IFormattable formattable => formattable.ToString(null, CultureInfo.InvariantCulture),
 		_ => value.ToString()
@@ -27,8 +29,8 @@ public sealed record NerdRow(string Label, string Value)
 		span = span.Duration();
 		return sign + (span.TotalSeconds switch
 		{
-			< 1 => $"{span.TotalMilliseconds:0} ms",
-			< 60 => $"{span.TotalSeconds.ToString("0.0", CultureInfo.InvariantCulture)} s",
+			< 1 => $"{span.TotalMilliseconds.ToFixed(0)} ms",
+			< 60 => $"{span.TotalSeconds.ToFixed(1)} s",
 			< 3600 => $"{span.Minutes} min {span.Seconds} s",
 			< 86400 => $"{(int)span.TotalHours} h {span.Minutes} min",
 			_ => $"{(int)span.TotalDays} d {span.Hours} h"
@@ -40,8 +42,8 @@ public sealed record NerdRow(string Label, string Value)
 	{
 		null => null,
 		< 1024 => $"{bytes} B",
-		< 1024 * 1024 => $"{(bytes.Value / 1024d).ToString("0.0", CultureInfo.InvariantCulture)} KiB",
-		_ => $"{(bytes.Value / 1048576d).ToString("0.0", CultureInfo.InvariantCulture)} MiB"
+		< 1024 * 1024 => $"{(bytes.Value / 1024d).ToFixed(1)} KiB",
+		_ => $"{(bytes.Value / 1048576d).ToFixed(1)} MiB"
 	};
 
 	/// <summary>The great-circle distance between two points in kilometres (haversine, Earth radius 6371 km).</summary>