viewer-panels: read-only boots panels open-collapsed; kicad-style layer rows

- Read-only sessions boot BOTH panels open as collapsed headers (a stored
  per-browser choice wins); inspector's default anchor moves to the
  top-left, layers keep the top-right stack under the FAB.
- Layer rows follow KiCad's Appearance-pane order: color swatch, eye
  toggle, layer name (name click = set active).
- read-only spec: boot-default assertions (open + collapsed + top-left
  anchor) in the lock test, chevron expansion in the panels test.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011gJ3M1RpeZLeNUUj8jKC4h

web/standalone/src/components/LayerPanel.tsx

@@ -78,7 +78,17 @@ export function parseLayersState(json: string): LayersState | null {
   }
 }
 
-export function LayerPanel({ mod, onClose }: { mod: LayersModule; onClose: () => void }) {
+export function LayerPanel({
+  mod,
+  defaultCollapsed,
+  onClose,
+}: {
+  mod: LayersModule;
+  /** Boot state when no per-browser choice is stored (read-only sessions
+   *  start as a collapsed header — viewer-panels). */
+  defaultCollapsed?: boolean;
+  onClose: () => void;
+}) {
   const rootRef = React.useRef<HTMLDivElement | null>(null);
   const drag = useDraggablePanel({
     storageKey: PANEL_POS_KEY,
@@ -87,10 +97,12 @@ export function LayerPanel({ mod, onClose }: { mod: LayersModule; onClose: () =>
   });
   const [collapsed, setCollapsedState] = React.useState<boolean>(() => {
     try {
-      return localStorage.getItem(PANEL_COLLAPSED_KEY) === "1";
+      const stored = localStorage.getItem(PANEL_COLLAPSED_KEY);
+      if (stored !== null) return stored === "1";
     } catch {
-      return false;
+      /* private mode */
     }
+    return defaultCollapsed === true;
   });
   const setCollapsed = (v: boolean) => {
     setCollapsedState(v);
@@ -201,22 +213,12 @@ export function LayerPanel({ mod, onClose }: { mod: LayersModule; onClose: () =>
                 state.active === l.id ? "bg-sky-500/10 dark:bg-sky-400/10" : ""
               }`}
             >
-              {/* Row body sets the ACTIVE layer (the wx Appearance pane's
-                  click semantics); the eye toggles visibility. */}
-              <button
-                data-testid="layer-activate"
-                className="flex min-w-0 flex-1 items-center gap-2 text-left hover:text-sky-600 dark:hover:text-sky-300"
-                title={`Make ${l.name} the active layer`}
-                onClick={() => setActive(l.id)}
-              >
-                <span
-                  className="h-3 w-3 shrink-0 rounded-sm ring-1 ring-inset ring-black/20 dark:ring-white/25"
-                  style={l.color ? { backgroundColor: l.color } : undefined}
-                />
-                <span className={`truncate ${state.active === l.id ? "font-semibold" : ""}`}>
-                  {l.name}
-                </span>
-              </button>
+              {/* KiCad Appearance-pane row order: color swatch, eye, name.
+                  The name sets the ACTIVE layer; the eye toggles visibility. */}
+              <span
+                className="h-3 w-3 shrink-0 rounded-sm ring-1 ring-inset ring-black/20 dark:ring-white/25"
+                style={l.color ? { backgroundColor: l.color } : undefined}
+              />
               <button
                 data-testid="layer-visibility"
                 aria-pressed={l.visible}
@@ -230,6 +232,16 @@ export function LayerPanel({ mod, onClose }: { mod: LayersModule; onClose: () =>
               >
                 {l.visible ? <Eye size={13} /> : <EyeOff size={13} />}
               </button>
+              <button
+                data-testid="layer-activate"
+                className="min-w-0 flex-1 text-left hover:text-sky-600 dark:hover:text-sky-300"
+                title={`Make ${l.name} the active layer`}
+                onClick={() => setActive(l.id)}
+              >
+                <span className={`block truncate ${state.active === l.id ? "font-semibold" : ""}`}>
+                  {l.name}
+                </span>
+              </button>
             </div>
           ))}
         </div>

web/standalone/src/components/SelectionInspector.tsx

@@ -37,12 +37,16 @@ const MAX_ITEMS = 20;
 
 export function SelectionInspector({
   doc,
+  defaultCollapsed,
   onClose,
 }: {
   /** The bound collab doc (pcbnew: the board room; eeschema: the ACTIVE
    *  sheet's room). Null when no doc room is bound (?collab=0) — the panel
    *  then shows selection counts only. */
   doc: Y.Doc | null;
+  /** Boot state when no per-browser choice is stored (read-only sessions
+   *  start as a collapsed header — viewer-panels). */
+  defaultCollapsed?: boolean;
   onClose: () => void;
 }) {
   const rootRef = React.useRef<HTMLDivElement | null>(null);
@@ -53,10 +57,12 @@ export function SelectionInspector({
   });
   const [collapsed, setCollapsedState] = React.useState<boolean>(() => {
     try {
-      return localStorage.getItem(PANEL_COLLAPSED_KEY) === "1";
+      const stored = localStorage.getItem(PANEL_COLLAPSED_KEY);
+      if (stored !== null) return stored === "1";
     } catch {
-      return false;
+      /* private mode */
     }
+    return defaultCollapsed === true;
   });
   const setCollapsed = (v: boolean) => {
     setCollapsedState(v);
@@ -103,11 +109,12 @@ export function SelectionInspector({
 
   const count = selection.uuids.length;
 
-  // Default anchor: below the overlay-menu FAB, clear of the layer panel's
-  // default (right 12 / top 56, w-64) — stack under it.
+  // Default anchor: TOP-LEFT (the layer panel owns the top-right stack under
+  // the overlay-menu FAB). Clear of the transient status chip (left-3 top-3,
+  // pointer-events-none anyway).
   const style: React.CSSProperties = drag.pos
     ? { left: drag.pos.x, top: drag.pos.y }
-    : { right: 12, top: 96 };
+    : { left: 12, top: 12 };
 
   return (
     <div

web/standalone/src/components/WasmTool.tsx

@@ -1182,12 +1182,17 @@ export function WasmTool({
   // Read-only sessions never bind presence, so the inspector's selection
   // store is fed by this minimal local handler (+ the C++ input hooks).
   const localSelectionRef = React.useRef<{ destroy(): void } | null>(null);
+  // Read-only sessions boot with BOTH panels open as collapsed headers
+  // (viewer-panels): discoverable without a trip through the menu; a stored
+  // per-browser choice wins over the default.
   const [layersOpen, setLayersOpenState] = React.useState<boolean>(() => {
     try {
-      return localStorage.getItem(LAYERS_OPEN_KEY) === "1";
+      const stored = localStorage.getItem(LAYERS_OPEN_KEY);
+      if (stored !== null) return stored === "1";
     } catch {
-      return false;
+      /* private mode */
     }
+    return readOnly === true;
   });
   const setLayersOpen = React.useCallback((v: boolean) => {
     setLayersOpenState(v);
@@ -1199,10 +1204,12 @@ export function WasmTool({
   }, []);
   const [inspectorOpen, setInspectorOpenState] = React.useState<boolean>(() => {
     try {
-      return localStorage.getItem(INSPECTOR_OPEN_KEY) === "1";
+      const stored = localStorage.getItem(INSPECTOR_OPEN_KEY);
+      if (stored !== null) return stored === "1";
     } catch {
-      return false;
+      /* private mode */
     }
+    return readOnly === true;
   });
   const setInspectorOpen = React.useCallback((v: boolean) => {
     setInspectorOpenState(v);
@@ -2767,13 +2774,21 @@ export function WasmTool({
           inspector for canvas-only sessions — the React stand-ins for the wx
           Appearance/Properties panes that kicadSetChrome(false) hides. */}
       {ready && effectiveChromeHidden && layersOpen && layersMod && (
-        <LayerPanel mod={layersMod} onClose={() => setLayersOpen(false)} />
+        <LayerPanel
+          mod={layersMod}
+          defaultCollapsed={readOnly}
+          onClose={() => setLayersOpen(false)}
+        />
       )}
       {ready &&
         effectiveChromeHidden &&
         inspectorOpen &&
         (tool === "pcbnew" || tool === "eeschema") && (
-          <SelectionInspector doc={panelDoc} onClose={() => setInspectorOpen(false)} />
+          <SelectionInspector
+            doc={panelDoc}
+            defaultCollapsed={readOnly}
+            onClose={() => setInspectorOpen(false)}
+          />
         )}
 
       {/* DEV: presence style tuner (VITE_PRESENCE_TUNER=1). */}