The card window's ⌘V drops its picture branch — the attachments header now offers one instead

Raw image data on a card window's ⌘V was a keyboard shortcut with no visible
trigger; the sidebar's Attachments header now grows a quiet control — beside
the existing add affordance, present only while the pasteboard holds a
picture this card could take — that pastes it through the exact seam the
retired branch used (ClipboardStore.pasteImage(intoCard:in:), the board's
"Paste Image into Card" row's own call). The file-URL branch stays on ⌘V; a
Finder copy is still unambiguous. CardBodyTextView's paste-yield mechanism
needed no change at all — it forwards by capability, not by picture-specific
logic, so a screenshot ⌘V with the body editor focused is now a genuine
no-op there, served by the new control instead.

The pasteboard's re-read gains a fourth checkpoint — a window becoming key —
alongside menu-tracking, ⌘-down and app activation: a persistent visible
control has to read true continuously while its window is frontmost, not
only at the instant a menu or chord probes it.

Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy

Kanban/UI/Card/CardAttachmentsSection.swift

@@ -80,7 +80,14 @@ struct CardAttachmentsSection: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: CardWindowMetrics.attachmentRowPadding(bodyPointSize: pointSize)) {
-            CardSidebarSectionHeader(title: "Attachments") { addAffordance }
+            CardSidebarSectionHeader(title: "Attachments") {
+                HStack(spacing: 8) {
+                    if attachments.canPasteImage?() == true {
+                        pasteImageAffordance
+                    }
+                    addAffordance
+                }
+            }
 
             if names.isEmpty {
                 emptyHint
@@ -96,6 +103,30 @@ struct CardAttachmentsSection: View {
 
     // MARK: - Header
 
+    /// **The paste-image affordance** — the ⌘V image-data branch's replacement (04-interactions.md ▸
+    /// Clipboard, re-ruled 2026-08-09): present only while the pasteboard holds a picture this card
+    /// could take, rather than a permanent row that would spend most of its life disabled. Its
+    /// visibility and its tap read and call the exact same seam, `CardAttachments.canPasteImage`/
+    /// `.pasteImage` — the header's own `CardPasteImageAffordance.isVisible` — so the button can never
+    /// promise a paste it does not deliver.
+    ///
+    /// **Present-or-absent, the hero rows' own posture** (below): a disabled picture-paste icon
+    /// sitting in this header the other 99% of the time a card window is open would be furniture
+    /// nobody reads, where "it showed up" is the whole point of the control replacing a keyboard
+    /// shortcut nobody could see.
+    private var pasteImageAffordance: some View {
+        Button {
+            attachments.pasteImage?()
+        } label: {
+            Image(systemName: "photo.badge.plus")
+                .font(.caption.weight(.semibold))
+                .foregroundStyle(.secondary)
+        }
+        .buttonStyle(.plain)
+        .help("Paste the copied picture as an attachment")
+        .accessibilityLabel("Paste Image as Attachment")
+    }
+
     /// The header's **quiet add affordance** — "a pointer twin of File ▸ Add Attachment…, no
     /// separate behavior" (11-command-nexus.md), which is why it calls the same method the menu row
     /// does rather than opening a panel of its own.