Update and cache-bust icons

- The old icon was too off-center; improve it.
- Add a mask icon
- Replace deprecated apple-touch-icon-precomposed.png with
  non-precomposed icon.
- Cache-bust all icons

assets/mask.svg

@@ -0,0 +1 @@
+<svg height="1024" width="1024" xmlns="http://www.w3.org/2000/svg"><path d="M348.4 721.7q-15.4 0-30-4.6t-25.3-15.4q-10.8-10.8-15.4-25.3-4.6-14.6-4.6-30t4.6-30q4.6-14.6 15.4-25.3 10.8-10.8 25.3-15.4 14.6-4.6 30-4.6t30 4.6q14.6 4.6 25.3 15.4 10.8 10.8 15.4 25.3 4.6 14.6 4.6 30t-4.6 30q-4.6 14.6-15.4 25.3-10.8 10.8-25.3 15.4-14.6 4.6-30 4.6zm0-268.8q-15.4 0-30-4.6t-25.3-15.4q-10.8-10.8-15.4-25.3-4.6-14.6-4.6-30t4.6-30q4.6-14.6 15.4-25.3 10.8-10.8 25.3-15.4 14.6-4.6 30-4.6t30 4.6q14.6 4.6 25.3 15.4 10.8 10.8 15.4 25.3 4.6 14.6 4.6 30t-4.6 30q-4.6 14.6-15.4 25.3-10.8 10.8-25.3 15.4-14.6 4.6-30 4.6zM654.8 873l-58.4-44.5q45.3-53.8 64.5-107.5-17.7-2.3-33-12.3-14.6-10.8-21.5-27.6-6.1-16.9-6.1-34.6 0-15.4 4.6-30t15.4-25.3q10.8-10.8 25.3-15.4 14.6-4.6 30-4.6t30 4.6q14.6 4.6 25.3 15.4 10.8 10.8 15.4 25.3 4.6 14.6 4.6 30v3.8q-1.5 111.4-96 222.7zm20.7-420.1q-15.4 0-30-4.6t-25.3-15.4q-10.8-10.8-15.4-25.3-4.6-14.6-4.6-30t4.6-30q4.6-14.6 15.4-25.3 10.8-10.8 25.3-15.4 14.6-4.6 30-4.6t30 4.6q14.6 4.6 25.3 15.4 10.8 10.8 15.4 25.3 4.6 14.6 4.6 30t-4.6 30q-4.6 14.6-15.4 25.3-10.8 10.8-25.3 15.4-14.6 4.6-30 4.6z"/></svg>

themes/etch-custom/layouts/partials/head.html

@@ -4,14 +4,20 @@
 	{{ with .Site.Params.description -}}
 	<meta name="description" content="{{ . }}">
 	{{ end }}
-	{{ printf `<link rel="shortcut icon" href="%s">` ("favicon.png" | absURL) | safeHTML }}
+	{{- $favicon := resources.Get "/favicon.png" | resources.Fingerprint "sha384" -}}
+	{{ printf `<link rel="shortcut icon" href="%s" integrity="%s">` $favicon.RelPermalink $favicon.Data.Integrity | safeHTML }}
 	<link href="{{ .Site.BaseURL }}posts/index.xml" rel="alternate" type="application/rss+xml" title="{{ $.Site.Title }}"/>
 	{{ if eq .Site.BaseURL "https://envs.net/~seirdy/" -}}
 	<meta name="robots" content="noindex">
 	{{ else -}}
 	<link rel="canonical" href="https://seirdy.one{{ .RelPermalink }}"/>
 	{{ end -}}
-	{{ printf `<link rel="apple-touch-icon-precomposed" href="%s">` ("apple-touch-icon-precomposed.png" | absURL) | safeHTML }}
+	<!--It used to be appple-specific, but now it's a pseudo-standard
+	 relied upon by other vendors too.-->
+	{{- $apple_icon := resources.Get "/apple-touch-icon.png" | resources.Fingerprint "sha384" -}}
+	{{ printf `<link rel="apple-touch-icon" href="%s" integrity="%s">` $apple_icon.RelPermalink $apple_icon.Data.Integrity | safeHTML }}
+	{{- $mask_icon := resources.Get "/mask.svg" | resources.Fingerprint "sha384" -}}
+	{{ printf `<link rel="mask" href="%s" integrity="%s">` $mask_icon.RelPermalink $mask_icon.Data.Integrity | safeHTML }}
 	{{ $resources := slice -}}
 	{{ $resources = $resources | append (resources.Get "/css/main.css") -}}
 	{{ $resources = $resources | append (resources.Get "/css/narrow.css") -}}