Assign every component and intrinsic element a deterministic identity
path (parent id + type name + key-or-position), composing top-down from
mount() through the constructed render tree. Expose the running
component's path via lifecycle.id and consume/strip the key prop in
createElement so it never reaches props or the DOM. Includes stable
keyed-list, nesting, namespace, and leak tests.

@@ -0,0 +1,263 @@
+// Headless in-browser test harness for Gooey.

@@ -0,0 +28,4 @@
+const VITE_STARTUP_TIMEOUT_MS = 30_000;
+
+// Gooey's own `s/test` runs the perf suite only with `--perf`; match that.
+const PERF_TEST = 'src/performance.test.tsx';

@@ -0,0 +260,4 @@
+    .catch((err) => {
+        console.error('Unexpected error:', err);
+        process.exit(1);
+    });

@@ -0,0 +1,285 @@
+# Increment 2 — State history & revert (design spec)

@@ -0,0 +5,4 @@
+ * engine itself depends on, like render-node identity) can register cleanup
+ * without introducing an import cycle back through `model/engine`.
+ */
+const resetCallbacks: (() => void)[] = [];

@@ -0,0 +41,4 @@
+    const c = collection([1, 2]);
+    assert.is(getAuthoritativeCells().length, 0);
+
+    c.retain();

@@ -0,0 +56,4 @@
+    const d = dict<string, number>([['a', 1]]);
+    assert.is(getAuthoritativeCells().length, 0);
+
+    d.retain();

@@ -0,0 +72,4 @@
+    const backing = getModelDict(m);
+    assert.is(getAuthoritativeCells().length, 0);
+
+    backing.retain();

@@ -0,0 +26,4 @@
+>();
+
+export function registerAuthoritative(
+    cell: object,

@@ -0,0 +40,4 @@
+    const kind = cells.get(cell);
+    if (kind === undefined) return;
+    cells.delete(cell);
+    for (const listener of [...listeners]) {

@@ -70,0 +79,4 @@
+ */
+export interface DictAuthoritativeOverride {
+    cell: object | null;
+    kind: AuthoritativeKind;

@@ -288,0 +324,4 @@
+export function dict<K, V>(
+    entries: [K, V][] = [],
+    debugName?: string,
+    authoritativeOverride?: DictAuthoritativeOverride | undefined

@@ -34,0 +37,4 @@
+        cell: null as object | null,
+        kind: 'model' as const,
+    };
+    const modelDict = dict(

@@ -0,0 +19,4 @@
+    reset();
+    subscribe();
+    subscribeCommit();
+});

@@ -0,0 +505,4 @@
+ * Like `buildForkTree`, but with a `tags` collection mutated on both branches
+ * (push / splice / reverse / moveSlice) alongside the fields.
+ */
+function buildMixedForkTree(keyframeInterval: number) {

@@ -0,0 +104,4 @@
+    unsubscribe: (() => void) | undefined;
+}
+
+const DEFAULT_KEYFRAME_INTERVAL = 24;

@@ -0,0 +167,4 @@
+function ensureListener(): void {
+    if (listenerRegistered) return;
+    listenerRegistered = true;
+    registerAfterFlush(() => {

@@ -0,0 +106,4 @@
+
+const DEFAULT_KEYFRAME_INTERVAL = 24;
+
+const fields = new Map<string, BoundCell>();

@@ -0,0 +231,4 @@
+    let isInitial = true;
+    bound.unsubscribe = bound.subscribe(() => {
+        if (isInitial) {
+            isInitial = false;

@@ -0,0 +322,4 @@
+
+/** Replaces a collection's contents in place, chunked to avoid spread limits. */
+function replaceCollection<T>(cell: Collection<T>, value: unknown): void {
+    const items = Array.isArray(value) ? (value as T[]) : [];

@@ -0,0 +419,4 @@
+}
+
+/**
+ * A session-stable name for an unbound cell: its `__debugName` when meaningful

@@ -0,0 +453,4 @@
+    if (cellNames.has(cell)) return;
+    const name = deriveName(cell, kind);
+    let bound: BoundCell;
+    switch (kind) {

@@ -22,1 +31,4 @@
                     );
+                    // Re-label all children so unkeyed siblings track their
+                    // post-splice positions.
+                    relabelContainer(renderNode);

@@ -51,0 +54,4 @@
+    // the DOM (as a bogus attribute). Preferring keys over sibling position is
+    // what makes identities stable across list reorders; see
+    // `viewcontroller/identity.ts`.
+    let key: unknown;

@@ -0,0 +10,4 @@
+import { getModelDict, model } from './model';
+
+/**
+ * Gooey state-history (SPIKE)

@@ -0,0 +13,4 @@
+ * Gooey state-history (SPIKE)
+ * ---------------------------
+ *
+ * Records changes to *authoritative global state* as a stream of batched,