Add pinnable right-side stack panel with hover functionality

dicom-viewer/src/App.tsx

@@ -176,6 +176,11 @@ function App({ container_id, imageStacks, autoCacheStack, annotationJson, viewer
   // Control visibility of the global top stack bar (hidden by default)
   const [topBarVisible, setTopBarVisible] = useState(false);
 
+  // Right-side stack panel pinned state (false = auto-hide, true = pinned open)
+  const [stackPanelPinned, setStackPanelPinned] = useState(false);
+  // Local hover state for temporary reveal when not pinned
+  const [stackPanelHover, setStackPanelHover] = useState(false);
+
   const [fullscreenHoverIdx, setFullscreenHoverIdx] = useState<number | null>(null);
   const [openDropdownIdx, setOpenDropdownIdx] = useState<number | null>(null);
 
@@ -3107,6 +3112,111 @@ function App({ container_id, imageStacks, autoCacheStack, annotationJson, viewer
         Show Stacks
       </button>
 
+      {/* Right-side stack panel (pinnable, shows on hover when not pinned) */}
+      <div
+        onMouseEnter={() => setStackPanelHover(true)}
+        onMouseLeave={() => setStackPanelHover(false)}
+        style={{
+          position: "absolute",
+          right: 0,
+          top: 12,
+          height: 'calc(100% - 24px)',
+          width: 320,
+          zIndex: 2100,
+          display: 'flex',
+          alignItems: 'stretch',
+          pointerEvents: 'auto',
+        }}
+      >
+        {/* Panel container: translateX to hide when not pinned and not hovered */}
+        <div
+          style={{
+            height: '100%',
+            width: '100%',
+            background: '#1f2428',
+            color: '#fff',
+            boxShadow: '0 2px 14px rgba(0,0,0,0.45)',
+            borderLeft: '1px solid #2f3336',
+            transform: stackPanelPinned || stackPanelHover ? 'translateX(0)' : 'translateX(96%)',
+            transition: 'transform 220ms ease',
+            display: 'flex',
+            flexDirection: 'column',
+            overflow: 'hidden',
+          }}
+        >
+          <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '8px 12px', borderBottom: '1px solid #2b2f31' }}>
+            <div style={{ fontWeight: 700 }}>Stacks</div>
+            <div style={{ display: 'flex', gap: 8, alignItems: 'center' }}>
+              <button
+                title={stackPanelPinned ? 'Unpin panel' : 'Pin panel'}
+                onClick={() => setStackPanelPinned(p => !p)}
+                style={{ background: stackPanelPinned ? '#1976d2' : '#333', color: '#fff', border: 'none', padding: '6px 8px', borderRadius: 4, cursor: 'pointer' }}
+              >
+                {stackPanelPinned ? 'Pinned' : 'Pin'}
+              </button>
+              <button
+                title="Close"
+                onClick={() => { setStackPanelPinned(false); setStackPanelHover(false); }}
+                style={{ background: 'transparent', color: '#fff', border: 'none', cursor: 'pointer', fontSize: 18 }}
+              >
+                ×
+              </button>
+            </div>
+          </div>
+
+          <div style={{ overflowY: 'auto', padding: 8, flex: 1 }}>
+            {availableStacks.length === 0 ? (
+              <div style={{ color: '#999', padding: 12 }}>No stacks available</div>
+            ) : (
+              <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
+                {availableStacks.map((stack, idx) => {
+                  const imageIds = Array.isArray(stack.imageIds) ? stack.imageIds : [];
+                  const label = stack.name || (stack.caseId ? `Case: ${stack.caseId}` : `Stack ${idx + 1}`);
+                  const count = imageIds.length;
+                  const invalid = !Array.isArray(imageIds) || count === 0;
+                  const isSelected = selectedStackIdx.includes(idx);
+                  return (
+                    <div
+                      key={idx}
+                      draggable={!invalid}
+                      onDragStart={e => {
+                        if (invalid) return;
+                        e.dataTransfer.setData('text/stack-idx', String(idx));
+                        e.dataTransfer.effectAllowed = 'copy';
+                      }}
+                      onClick={() => { if (!invalid) handleLoadStack(0, idx); }}
+                      style={{
+                        display: 'flex',
+                        alignItems: 'center',
+                        justifyContent: 'space-between',
+                        padding: '8px 10px',
+                        background: isSelected ? '#1976d2' : 'transparent',
+                        color: isSelected ? '#fff' : '#ddd',
+                        borderRadius: 6,
+                        cursor: invalid ? 'not-allowed' : 'pointer',
+                      }}
+                    >
+                      <div style={{ display: 'flex', flexDirection: 'column' }}>
+                        <div style={{ fontWeight: 600 }}>{label}</div>
+                        <div style={{ fontSize: 12, opacity: 0.7 }}>{count} img{count === 1 ? '' : 's'}</div>
+                      </div>
+                      <div style={{ fontSize: 12, opacity: 0.8 }}>{stack.studyId || ''}</div>
+                    </div>
+                  );
+                })}
+              </div>
+            )}
+          </div>
+        </div>
+
+        {/* Visible handle when panel is hidden to allow hover */}
+        {!stackPanelPinned && (
+          <div style={{ width: 24, height: 64, background: 'transparent', display: 'flex', alignItems: 'center', justifyContent: 'center', cursor: 'pointer' }}>
+            <div style={{ width: 6, height: 36, background: '#444', borderRadius: 4, opacity: 0.9 }} />
+          </div>
+        )}
+      </div>
+
   <div>
         {/* Side menu toggle button */}
         <button