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/Composer.razor

@@ -162,7 +162,7 @@
 				}
 				else
 				{
-					<span>@Localizer["Shown only to people within {0} km of here, never sent to other servers.", form.RangeKm.ToString("0")]</span>
+					<span>@Localizer["Shown only to people within {0} km of here, never sent to other servers.", form.RangeKm.ToDefaultCount()]</span>
 				}
 			</span>
 			<DRange TValue="double" Size="DSize.Xs" Min="1" Max="50" Step="1" @bind-Value="form.RangeKm" />