fix: hollow sheet rooms wiped subsheets on entry (ysync 0011) + hierarchy pane icon sizing/selection colours

Collab: a save-all's layout-only sync into a never-entered sheet room left a
doc with layout but zero items; the first entry adopted it and removed every
item on screen. seed() now file-seeds a hollow doc, syncLayoutFromSave skips
never-seeded empty rooms, and the ydoc-boot / sibling-restage paths fall back
to the file. Tree: new tree-hier standalone app + e2e spec covering the
wxwidgets bundle-size and unfocused-selection fixes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0189z2siCsezE39ugcDKNBMs

web/standalone/src/components/wasm-tool/collab-start.ts

@@ -4,6 +4,7 @@ import {
   docToFile,
   fileToDoc,
   ydocHasState,
+  ydocIsHollow,
   yToDoc,
   type KicadDoc,
   type Tool,
@@ -87,7 +88,7 @@ export async function maybeConnectDocSession(
   // populated drawing sheet (pl_editor `.kicad_wks`) has zero uuid items, so an
   // items-only check makes a joining tab refetch the stale file instead of
   // materializing the shared doc's current state.
-  if (!ydocHasState(session.doc)) {
+  if (!ydocHasState(session.doc) || ydocIsHollow(session.doc)) {
     opts.log(`[ydoc] room ${room} is empty — falling back to the API fetch (will file-seed)`);
     return { session };
   }

web/standalone/src/wasm/collab/kicad-binding.test.ts

@@ -9,7 +9,9 @@ import {
   renderItem,
   SEXPR_VERSION_CURRENT,
   sexprToItems,
+  syncLayoutToY,
   ydocHasState,
+  ydocIsHollow,
   ydocSexprVersion,
   yToDoc,
   type KicadItem,
@@ -198,6 +200,49 @@ describe("bindKicadCollab — two editors over relayed Y.Docs", () => {
     expect(edB.store["fp-1"]).toBeDefined(); // adopted
   });
 
+  it("a HOLLOW room (layout only from a save-all sync, never seeded) is file-seeded, NOT adopted", () => {
+    // Save-all fired the layout sync into a room nobody had entered: the doc got
+    // meta/layout but zero items and no seedNonce. Adopting it removed every
+    // item on the subsheet the editor had just shown (arduino subsheet blank bug).
+    const { a, edA, edB, bindA, bindB } = setup();
+    const file = `(kicad_wks (version 20220228) (generator "pl_editor")
+  (setup (textsize 1.5 1.5) (linewidth 0.15))
+  (rect (uuid "r-1") (name "border") (start 0 0 ltcorner) (end 0 0 rbcorner))
+)
+`;
+    const seedDoc = fileToDoc(file);
+    syncLayoutToY(seedDoc, a, "layout-save"); // the hollow footprint
+    expect(ydocHasState(a)).toBe(true);
+    expect(ydocIsHollow(a)).toBe(true);
+
+    Object.assign(edA.store, seedDoc.items); // editor shows the file
+    bindA.seed(seedDoc);
+
+    expect(edA.applied.length).toBe(0); // nothing removed from the editor
+    expect(edA.store["r-1"]).toBeDefined();
+    expect(ydocIsHollow(a)).toBe(false); // healed: items + seed marker in the doc
+    expect(docToFile(yToDoc(a))).toBe(docToFile(seedDoc));
+    bindB.seed(); // a peer joining now adopts the real content
+    expect(edB.store["r-1"]).toBeDefined();
+  });
+
+  it("a seeded room that was legitimately emptied is still adopted (not mistaken for hollow)", () => {
+    const { a, edA, edB, bindA, bindB } = setup();
+    const file = `(kicad_wks (version 20220228) (generator "pl_editor")
+  (rect (uuid "r-1") (name "border") (start 0 0 ltcorner) (end 0 0 rbcorner))
+)
+`;
+    const seedDoc = fileToDoc(file);
+    Object.assign(edA.store, seedDoc.items);
+    bindA.seed(seedDoc); // file-seeded → seed marker present
+    edA.localRemove("r-1"); // the peer deletes everything on the sheet
+    expect(ydocHasState(a)).toBe(true);
+    expect(ydocIsHollow(a)).toBe(false); // seeded, merely empty
+    Object.assign(edB.store, seedDoc.items); // B cold-opens the stale file
+    bindB.seed(seedDoc);
+    expect(edB.store["r-1"]).toBeUndefined(); // doc authority: the deletion wins
+  });
+
   it("pre-seed remote state does NOT stream into the editor (adopt covers it)", () => {
     const { edA, edB, bindA, bindB } = setup();
     seedEditor(edA, FP);

web/standalone/src/wasm/collab/kicad-binding.ts

@@ -20,6 +20,7 @@ import {
   Y_KDOC_REVERT_REASON,
   Y_KDOC_SEED_NONCE,
   ydocHasState,
+  ydocIsHollow,
   ydocSexprVersion,
   yToItemUnchecked,
   type ItemsWireDelta,
@@ -264,7 +265,14 @@ export function bindKicadCollab(
     // `ydocHasState` (meta + layout + items), NOT `items.size`: a populated
     // drawing sheet (pl_editor .kicad_wks) has zero uuid items, so an items-only
     // check would mis-classify a seeded room as empty and re-seed/clobber it.
-    if (opts?.editorMatchesDoc && ydocHasState(doc)) {
+    // A HOLLOW doc (layout/meta, zero items, never seeded — a save-all's
+    // layout sync into a room nobody had entered) counts as empty here:
+    // adopting it would remove every item on the sheet the editor just
+    // showed (the "subsheet renders then goes blank" bug), and a file
+    // materialized from it is title-block-only.
+    const hollow = ydocIsHollow(doc);
+    if (hollow) clog("seed: doc is HOLLOW (layout only, never seeded) → treating as empty");
+    if (opts?.editorMatchesDoc && ydocHasState(doc) && !hollow) {
       // The editor opened exactly this doc's content (Y.Doc-load path): no
       // adopt apply needed. snapshotItems() still runs to BASELINE the wasm
       // differ — otherwise the first local edit would re-emit the full model.
@@ -276,7 +284,7 @@ export function bindKicadCollab(
       }
       return;
     }
-    if (!ydocHasState(doc) && seedDoc) {
+    if ((!ydocHasState(doc) || hollow) && seedDoc) {
       if (readOnly) {
         // A viewer never authors a room. The editor keeps showing the file it
         // opened; when a writer later seeds this room, the (now-open) UP
@@ -336,7 +344,7 @@ export function bindKicadCollab(
       return;
     }
 
-    const hasState = ydocHasState(doc);
+    const hasState = ydocHasState(doc) && !hollow;
 
     if (!hasState) {
       if (readOnly) {
@@ -349,6 +357,12 @@ export function bindKicadCollab(
       doc.transact(() => {
         applyDeltaToY(doc, local, ORIGIN);
         upsertLibSymbolsToY(doc, wireLibSymbols(wire), ORIGIN);
+        // Stamp the seed marker like the file path does: a seeded-then-emptied
+        // sheet must stay distinguishable from a hollow one (ydocIsHollow).
+        doc.getMap(Y_KDOC_META).set(
+          Y_KDOC_SEED_NONCE,
+          `${doc.clientID}:${Math.random().toString(36).slice(2)}`,
+        );
       }, ORIGIN);
       return;
     }

web/standalone/src/wasm/collab/sheet-manager.test.ts

@@ -10,8 +10,16 @@ const { connectKicadDoc, bindKicadCollab, moduleItemsBridge } = vi.hoisted(() =>
 
 vi.mock("./index", () => ({ connectKicadDoc }));
 vi.mock("./kicad-binding", () => ({ bindKicadCollab, moduleItemsBridge }));
+const { ydocHasState, syncLayoutToY, fileToDoc } = vi.hoisted(() => ({
+  ydocHasState: vi.fn(() => false),
+  syncLayoutToY: vi.fn(() => true),
+  fileToDoc: vi.fn((t: string) => ({ text: t })),
+}));
 vi.mock("@pcbjam/shared", () => ({
   collabRoomId: (s: string, p: string, d: string) => `${s}:${p}:${d}`,
+  ydocHasState,
+  syncLayoutToY,
+  fileToDoc,
 }));
 
 import { createSheetCollabManager } from "./sheet-manager";
@@ -195,6 +203,35 @@ describe("sheet-manager warm pool", () => {
   });
 });
 
+describe("sheet-manager layout save-sync (hollow-room guard)", () => {
+  beforeEach(() => {
+    ydocHasState.mockReset().mockReturnValue(false);
+    syncLayoutToY.mockReset().mockReturnValue(true);
+  });
+
+  it("skips a warmed-but-never-entered sheet whose doc is empty (save-all before first entry)", async () => {
+    const m = makeManager();
+    await m.connectAll(["root.kicad_sch", "Headers.kicad_sch"]);
+    await m.switchTo("root.kicad_sch");
+    // KiCad's SaveProject writes EVERY sheet → the hook fires for Headers too.
+    m.syncLayoutFromSave("Headers.kicad_sch", "(kicad_sch …)");
+    // Nothing written: a layout-only doc would be adopted as "remove everything"
+    // on the first entry into Headers.
+    expect(syncLayoutToY).not.toHaveBeenCalled();
+  });
+
+  it("still syncs the bound (seeded) sheet and any sheet whose doc already has state", async () => {
+    const m = makeManager();
+    await m.connectAll(["root.kicad_sch", "Headers.kicad_sch"]);
+    await m.switchTo("root.kicad_sch");
+    m.syncLayoutFromSave("root.kicad_sch", "(kicad_sch …)");
+    expect(syncLayoutToY).toHaveBeenCalledTimes(1);
+    ydocHasState.mockReturnValue(true); // Headers was seeded by a peer
+    m.syncLayoutFromSave("Headers.kicad_sch", "(kicad_sch …)");
+    expect(syncLayoutToY).toHaveBeenCalledTimes(2);
+  });
+});
+
 describe("sheet-manager lifecycle hardening (findings C-1/C-4/C-5)", () => {
   it("a connect resolving after destroy() is torn down, not registered (C-1)", async () => {
     let release!: () => void;

web/standalone/src/wasm/collab/sheet-manager.ts

@@ -3,6 +3,7 @@ import {
   collabRoomId,
   fileToDoc,
   syncLayoutToY,
+  ydocHasState,
   type KicadDoc,
   type PresenceUser,
 } from "@pcbjam/shared";
@@ -372,6 +373,15 @@ export function createSheetCollabManager(opts: SheetManagerOptions): SheetCollab
     const room = rooms.get(sheetPath);
     if (!room) return; // not a collab sheet (or still onboarding) — nothing to sync
     const write = (): void => {
+      // A room nobody has entered yet (never bound this session) and whose
+      // doc is still empty has nothing to reconcile: a layout-only write
+      // would leave a HOLLOW doc (layout, zero items) that every later first
+      // entry would adopt by removing the whole sheet. The first bind
+      // file-seeds it — layout included — so nothing is lost by skipping.
+      if (!room.seeded && !ydocHasState(room.doc)) {
+        clog(`[sheet] layout save-sync: ${sheetPath} skipped (room never seeded)`);
+        return;
+      }
       try {
         // Writing to a PARKED room's doc marks it dirty via startWatch — fine:
         // the diff-on-rebind adopt makes the catch-up cost the real delta only.

web/standalone/src/wasm/collab/sibling-restage.test.ts

@@ -13,6 +13,7 @@ vi.mock("../kicad-runner", () => ({ restageFile }));
 vi.mock("@pcbjam/shared", () => ({
   collabRoomId: (s: string, p: string, d: string) => `${s}:${p}:${d}`,
   ydocHasState,
+  ydocIsHollow: () => false,
   yToDoc: (doc: unknown) => doc,
   docToFile: () => "(kicad_sch materialized)",
 }));

web/standalone/src/wasm/collab/sibling-restage.ts

@@ -1,4 +1,4 @@
-import { collabRoomId, docToFile, ydocHasState, yToDoc } from "@pcbjam/shared";
+import { collabRoomId, docToFile, ydocHasState, ydocIsHollow, yToDoc } from "@pcbjam/shared";
 import type * as Y from "yjs";
 import { restageFile } from "../kicad-runner";
 import { connectKicadDoc, type KicadDocSession } from "./index";
@@ -102,6 +102,9 @@ export async function startSiblingRestage(opts: {
       // An empty room means no one ever seeded this sheet — the boot-staged
       // API snapshot is the freshest copy there is; leave it alone.
       if (!ydocHasState(doc)) return;
+      // A hollow doc (layout only, never seeded) would restage a title-block-only
+      // file over the real one — the staged copy is the freshest there is.
+      if (ydocIsHollow(doc)) return;
       const text = docToFile(yToDoc(doc));
       restageFile(win, slug, sheetPath, new TextEncoder().encode(text), log);
     } catch (err) {