fix #221: scale image pastes, drop text box, fix raw view and size

- image pastes render the image scaled to fit the viewer box (aspect
  ratio preserved, max-height 70vh), no text/code box below it
- link pill moved under the image as a small inline chip
- /raw serves image attachment bytes as an image instead of empty text
- view details size reports the actual attachment file size

internal/web/static/app.css

@@ -810,15 +810,35 @@ button[type="submit"]:focus-visible,
 }
 .file-chip .file-chip-remove:hover { color: var(--danger, #c0392b); }
 .attachment-bar { display: flex; flex-direction: column; gap: 10px; }
-.attachment-chip {
+/* #221: the link pill under an image preview stays a small inline chip,
+   left-aligned under the image, not stretched above it. */
+.attachment-bar .attachment-chip {
   display: inline-flex; align-items: center; gap: 12px; align-self: flex-start;
   border: 1px solid var(--border); border-radius: var(--radius);
-  padding: 8px 16px; text-decoration: none; color: var(--fg);
-  background: var(--surface-2); font-size: 21.6px;
+  padding: 6px 14px; text-decoration: none; color: var(--fg);
+  background: var(--surface-2); font-size: 19px;
+}
+.attachment-bar .attachment-chip:hover { border-color: var(--accent); }
+.attachment-bar .attachment-chip .attachment-name {
+  max-width: 320px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
+}
+/* #221: images scale to fit the viewer box, aspect ratio preserved. */
+.attachment-preview {
+  max-width: 100%;
+  align-self: flex-start;
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  background: var(--surface-2);
+  overflow: hidden;
+}
+.attachment-preview img {
+  display: block;
+  max-width: 100%;
+  max-height: 70vh;
+  width: auto;
+  height: auto;
+  object-fit: contain;
 }
-.attachment-chip:hover { border-color: var(--accent); }
-.attachment-chip .attachment-size { color: var(--muted-fg); font-size: 19px; }
-.attachment-preview img { max-width: 480px; max-height: 360px; border-radius: var(--radius); border: 1px solid var(--border); }
 
 /* #139: CSP-safe replacements for inline style attributes (style-src 'self') */
 .hidden { display: none; }

internal/web/templates/paste.html

@@ -39,19 +39,27 @@
   {{if .Attachment}}
   <div class="float">
     <div class="attachment-bar">
+      {{if .AttachmentImage}}
+      <div class="attachment-preview"><img src="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" alt="{{.Attachment.Filename}}"></div>
+      <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>
+      {{else}}
       <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")}}
       <div class="attachment-preview"><img src="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" alt="{{.Attachment.Filename}}"></div>
       {{end}}
     </div>
   </div>
   {{end}}
+  {{if not .AttachmentImage}}
   <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>

internal/web/web.go

@@ -252,20 +252,35 @@ func (h *Handlers) renderPaste(w http.ResponseWriter, row *store.PasteRow, justC
 		http.Error(w, "db error", 500)
 		return
 	}
+	// #221: image attachments render the image, not a text/code box. Size
+	// comes from the attachment's actual file size, not the text content.
+	attImage := false
+	if attachment != nil {
+		switch attachment.Mime {
+		case "image/png", "image/jpeg", "image/gif", "image/webp":
+			attImage = true
+		}
+	}
+	sizeHuman := humanSize(len(row.Content))
+	lineCount := lines
+	if attachment != nil {
+		sizeHuman = attachment.SizeHuman
+		lineCount = 1
+	}
 	data := map[string]any{
 		"Page":          "paste",
 		"ID":            row.ID,
 		"Title":         row.Title.String,
 		"Language":      row.Language.String,
 		"StatsSummary":  summary,
-		"SizeHuman":     humanSize(len(row.Content)),
+		"SizeHuman":     sizeHuman,
 		"HasPassword":   row.PasswordHash.Valid,
 		"BurnAfterRead": row.BurnAfterRead,
 		"CustomSlug":    row.CustomSlug.String,
 		"ContentHTML":   template.HTML(langpkg.HighlightCode(row.Content, row.Language.String)), // safe: HighlightCode escapes all non-span text
 		"ContentAttr":   row.Content,
 		"Gutter":        strings.TrimSuffix(gutter, "\n"),
-		"LineCount":     lines,
+		"LineCount":     lineCount,
 		"SizeBytes":     len(row.Content),
 		"CreatedAgo":    agoString(row.CreatedAt),
 		"CreatedAtUnix": row.CreatedAt,
@@ -279,6 +294,7 @@ func (h *Handlers) renderPaste(w http.ResponseWriter, row *store.PasteRow, justC
 		"ReadsTotal":    int(row.ReadsLimit.Int64),
 		"JustCreated":   justCreated,
 		"Attachment":    attachment,
+		"AttachmentImage": attImage,
 		"Host":          "this host",
 	}
 	h.renderPage(w, "paste.html", data)