#221: image paste view fixes

- image pastes scale to fit the viewer box (max-width/max-height, object-fit)
- no text/code box rendered below the image for image pastes
- link pill positioning cleaned up on the image view
- /raw for attachment pastes redirects to the file itself
- view details size now uses the attachment blob size, not empty text len

internal/web/templates/paste.html

@@ -38,20 +38,22 @@
   {{end}}
   {{if .Attachment}}
   <div class="float">
-    <div class="attachment-bar">
+    <div class="attachment-bar{{if .IsImagePaste}} is-image{{end}}">
       <a class="attachment-chip" href="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" data-mime="{{.Attachment.Mime}}">
         <span class="attachment-name">{{.Attachment.Filename}}</span>
         <span class="attachment-size">{{.Attachment.SizeHuman}}</span>
       </a>
-      {{if or (eq .Attachment.Mime "image/png") (eq .Attachment.Mime "image/jpeg") (eq .Attachment.Mime "image/gif") (eq .Attachment.Mime "image/webp")}}
+      {{if .IsImagePaste}}
       <div class="attachment-preview"><img src="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" alt="{{.Attachment.Filename}}"></div>
       {{end}}
     </div>
   </div>
   {{end}}
+  {{if not .IsImagePaste}}
   <div class="float">
     <div class="code" id="code"><div class="gutter" id="gutter">{{.Gutter}}</div><div class="codebody" id="codebody">{{.ContentHTML}}</div></div>
   </div>
+  {{end}}
 </div>
 <input type="hidden" id="raw-content" value="{{.ContentAttr}}">
 <script src="/static/paste.js" defer data-paste-id="{{.ID}}"></script>