dock: the practice fold morphs like teaching — every docked variant carries its fold state

Owner report 2026-10-06: practice sessions 'open and close instantly'
while teaching morphs. Live instrumented run (Element.prototype.animate
wrapped, three transitions recorded) proved the pose/conclude morphs
fire identically in practice (54px↔327.5px, 120ms, same easing) — the
asymmetry was the FOLD: the shell's height-morph key read
`mode:${pending ? expanded : "-"}` and pending (the question's tool
call) is null in practice, so a practice dock's bar↔form toggle never
changed the key — no height morph, instant jump, only the 160ms content
fade. The ternary predates practice sessions (aeef28d, August); the
remembered Oct-5 fix (ec8315b) added the fade only. Round 16's pause
flow raised fold exposure until the seam surfaced.

Fix: dockStateKey(mode, docked, expanded) — components/dock-state-key.ts
— widened to !!pending || !!practice (the fold machine's own ownership
rule). Typing growth keeps the key (never animates); the fold rides the
exact branch teaching has used for months. Pinned in
tests/dock-state-key.test.ts.

tests/dock-state-key.test.ts

@@ -0,0 +1,38 @@
+/**
+ * The dock shell's variant key — the WAAPI height-morph trigger. Pinned
+ * after the practice-fold fix (owner, 2026-10-06): the expanded term
+ * belongs to every docked variant, so a practice dock's fold/unfold
+ * morphs exactly like a teaching question's. Before the fix the key
+ * read `pending ? expanded : "-"` — pending is null in practice, the
+ * key never changed on the fold, and the practice dock's height jumped
+ * instantly between form and bar while teaching morphed.
+ */
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+
+import { dockStateKey } from "../components/dock-state-key.ts";
+
+describe("dockStateKey (the height-morph trigger)", () => {
+	it("a docked variant carries its fold state — practice included", () => {
+		assert.equal(dockStateKey("practice:call_p1", true, true), "practice:call_p1:true");
+		assert.equal(dockStateKey("practice:call_p1", true, false), "practice:call_p1:false");
+		assert.equal(dockStateKey("question:call_q1", true, true), "question:call_q1:true");
+		assert.equal(dockStateKey("question:call_q1", true, false), "question:call_q1:false");
+	});
+
+	it("the fold toggling the key is what animates: same variant + same fold = same key (typing growth never morphs)", () => {
+		assert.equal(
+			dockStateKey("practice:call_p1", true, true),
+			dockStateKey("practice:call_p1", true, true),
+		);
+		assert.notEqual(
+			dockStateKey("practice:call_p1", true, true),
+			dockStateKey("practice:call_p1", true, false),
+		);
+	});
+
+	it("an undocked band (the composer) has no fold term", () => {
+		assert.equal(dockStateKey("chat", false, true), "chat:-");
+		assert.equal(dockStateKey("chat", false, false), "chat:-");
+	});
+});