Fix #221: image pastes scale to fit, no code box, accurate size, raw serves image

- paste view: image attachments render in a scalable preview (max-height
  min(70vh, 720px), object-fit contain) and the code box is omitted;
  wrap/copy buttons hidden for image pastes
- SizeHuman/stats summary show the attachment size for file pastes
  (row.Content is empty for file pastes, was showing 0 B)
- /raw/{id} on a file paste streams the attachment bytes inline with its
  sniffed mime and filename instead of an empty text/plain body

internal/web/static/app.css

@@ -216,7 +216,8 @@ body {
 .tag { font-size: 19.8px; color: var(--muted-fg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 2px 9px; }
 .paste-title-bar { display: flex; align-items: center; gap: 12px; padding: 12px 18px; flex-wrap: wrap; }
 .paste-title-bar h1 { font-size: 29.2px; font-weight: 600; margin: 0; word-break: normal; overflow-wrap: anywhere; }
-.stats-pill { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
+/* #222: overflow:hidden clips the element's own 1px border thin at the radius; inset shadow isn't clipped */
+.stats-pill { border: 0; box-shadow: inset 0 0 0 1px var(--border); border-radius: var(--radius); overflow: hidden; }
 .stats-head { display: flex; align-items: center; gap: 16px; width: 100%; background: none; border: 0; border-bottom: 1px solid var(--border); color: var(--muted-fg); font: inherit; font-size: 21.6px; padding: 14px 18px; cursor: pointer; text-align: left; }
 .stats-head:hover { color: var(--fg); background: var(--surface-2); }
 .stats-chev { width: 18px; height: 18px; flex: none; transition: transform 0.15s ease; }
@@ -819,6 +820,17 @@ button[type="submit"]:focus-visible,
 .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); }
+/* #221: image pastes scale to fit the available box; no fixed pixel cap */
+.attachment-preview.is-image img {
+  display: block;
+  max-width: 100%;
+  max-height: min(70vh, 720px);
+  width: auto;
+  height: auto;
+  object-fit: contain;
+  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

@@ -6,9 +6,9 @@
       <h1>{{if .Title}}{{.Title}}{{else}}Untitled paste{{end}}</h1>
       {{if .CustomSlug}}<span class="slug">/{{.CustomSlug}}</span>{{end}}
       <div class="spacer"></div>
-      <button type="button" class="iconbtn wrap-toggle" title="Toggle line wrap" aria-pressed="false">wrap</button>
+      {{if not .AttachmentIsImage}}<button type="button" class="iconbtn wrap-toggle" title="Toggle line wrap" aria-pressed="false">wrap</button>{{end}}
       <a class="iconbtn" href="/raw/{{.ID}}">raw</a>
-      <a class="iconbtn" href="#" id="copy-btn">copy</a>
+      {{if not .AttachmentIsImage}}<a class="iconbtn" href="#" id="copy-btn">copy</a>{{end}}
       {{if .DeletionToken}}<a class="iconbtn danger" href="#" id="delete-btn">delete</a>{{end}}
     </div>
   </div>
@@ -44,14 +44,19 @@
         <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")}}
+      {{/* #221: image pastes scale to fit; no text/code box underneath */}}
+      <div class="attachment-preview is-image"><img src="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" alt="{{.Attachment.Filename}}"></div>
+      {{else}}
       <div class="attachment-preview"><img src="/f/{{.Attachment.ID}}/{{.Attachment.Filename}}" alt="{{.Attachment.Filename}}"></div>
       {{end}}
     </div>
   </div>
   {{end}}
+  {{if not .AttachmentIsImage}}{{/* #221: image pastes replace the code box entirely */}}
   <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

@@ -92,6 +92,25 @@ func humanSize(n int) string {
 	return fmt.Sprintf("%.1f MB", float64(n)/(1024*1024))
 }
 
+// #221: file pastes store their bytes in the blob store with empty text
+// content; the displayed size is the attachment size, not len(Content).
+func pasteDisplaySize(row *store.PasteRow, att *store.Attachment) int64 {
+	if row.Content == "" && att != nil {
+		return att.Size
+	}
+	return int64(len(row.Content))
+}
+
+// attachmentIsImage reports whether a paste-view attachment renders as an
+// image (same set the paste template previews inline, #221).
+func attachmentIsImage(mime string) bool {
+	switch strings.ToLower(strings.TrimSpace(mime)) {
+	case "image/png", "image/jpeg", "image/gif", "image/webp":
+		return true
+	}
+	return false
+}
+
 func (u *UI) StaticHandler() http.Handler {
 	sub, _ := fs.Sub(staticFS, "static")
 	return http.StripPrefix("/static/", http.FileServer(http.FS(sub)))
@@ -245,20 +264,22 @@ func (h *Handlers) renderPaste(w http.ResponseWriter, row *store.PasteRow, justC
 	if lang == "" {
 		lang = "text"
 	}
-	summary := fmt.Sprintf("%s · %s · %d views · %s", lang, humanSize(len(row.Content)), row.ViewCount, agoString(row.CreatedAt))
 	// #38: one optional file attachment per paste; nil when none.
 	attachment, err := h.Store.GetAttachmentForPaste(row.ID)
 	if err != nil {
 		http.Error(w, "db error", 500)
 		return
 	}
+	summary := fmt.Sprintf("%s · %s · %d views · %s", lang, humanSize(int(pasteDisplaySize(row, attachment))), row.ViewCount, agoString(row.CreatedAt))
 	data := map[string]any{
 		"Page":          "paste",
 		"ID":            row.ID,
 		"Title":         row.Title.String,
 		"Language":      row.Language.String,
 		"StatsSummary":  summary,
-		"SizeHuman":     humanSize(len(row.Content)),
+		// #221: file pastes store bytes in the blob store; report the
+		// attachment size, not the (empty) text content length.
+		"SizeHuman":     humanSize(int(pasteDisplaySize(row, attachment))),
 		"HasPassword":   row.PasswordHash.Valid,
 		"BurnAfterRead": row.BurnAfterRead,
 		"CustomSlug":    row.CustomSlug.String,
@@ -279,6 +300,8 @@ func (h *Handlers) renderPaste(w http.ResponseWriter, row *store.PasteRow, justC
 		"ReadsTotal":    int(row.ReadsLimit.Int64),
 		"JustCreated":   justCreated,
 		"Attachment":    attachment,
+		// #221: tells the template to drop the code box for image pastes
+		"AttachmentIsImage": attachment != nil && attachmentIsImage(attachment.Mime),
 		"Host":          "this host",
 	}
 	h.renderPage(w, "paste.html", data)