draft: the pick bar comes to the new-practice screen (round 10 slice 2)

The SAME pill the home screen carries — above the composer, dashed
'Pick propositions from the map' when empty, count + Clear when picked
— now lives on the /chat/new?mode=practice draft. The draft has no
graph behind it, so the pill opens the standalone ChainTableOverlay
(select mode, controlled selection, Done bar) over the /api/graph
snapshot, fetched lazily on first open. The first send carries the
picks as graphContext: the created session is born WITH its ids-first
context marker (target validation's truth set) instead of pickless —
the same contract as the home screen's practice send. Teach drafts
render no pill; practice with no picks stays lean on the wire.

components/new-session.tsx

@@ -9,7 +9,13 @@ import { TopBar } from "@/components/top-bar";
 import { SetupDialog } from "@/components/setup-dialog";
 import { useStrongKeyless, useZeroKeys, ZeroKeysPill } from "@/components/setup-cta";
 import { StatsBar } from "@/components/stats-bar";
-import type { ChatSettings } from "@/src/core";
+import { ChainTableOverlay } from "@/components/chain-table.tsx";
+import { DumbbellIcon } from "lucide-react";
+import type { ChatSettings, GraphSnapshot } from "@/src/core";
+
+/** The draft's pick set (owner round 10): the SAME shape the home pick
+ *  bar lifts — resolved nodes as the learner SAW them at pick time. */
+export type DraftPick = { id: string; name: string; statement: string };
 
 /**
  * The sessionless draft view at /chat/new (owner, 2026-09-13): "+ New
@@ -37,13 +43,22 @@ export async function startDraftSession(
 	text: string,
 	fetchLike: typeof fetch,
 	mode?: "practice",
+	picks?: readonly DraftPick[],
 ): Promise<string | null> {
 	const t = text.trim();
 	if (!t) return null;
+	// THE PICKS RIDE THE CREATE (owner round 10): a practice draft seeded
+	// from the pick bar creates its session WITH the graph context — the
+	// same contract as the home screen's practice send (the marker with
+	// [id] name: statement lines, target validation's truth set).
 	const res = await fetchLike("/api/chats", {
 		method: "POST",
 		headers: { "Content-Type": "application/json" },
-		body: JSON.stringify(mode === "practice" ? { title: t, kind: "practice" } : { title: t }),
+		body: JSON.stringify(
+			mode === "practice"
+				? { title: t, kind: "practice", ...(picks && picks.length > 0 ? { graphContext: { propositions: picks } } : {}) }
+				: { title: t },
+		),
 	});
 	const { id } = (await res.json()) as { id: string };
 	// No settings PUT on create (per-session models, owner 2026-09-28):
@@ -63,6 +78,9 @@ export function DraftShell({
 	onSend,
 	setupCta,
 	mode = "teach",
+	picks = [],
+	onOpenPicker,
+	onClearPicks,
 }: {
 	busy: boolean;
 	text: string;
@@ -76,6 +94,14 @@ export function DraftShell({
 	 *  affordance home carries, rendered above the draft shell — passed by
 	 *  NewSession, which owns the configured state and the SetupDialog. */
 	setupCta?: ReactNode;
+	/** THE PICK BAR (owner round 10): the SAME pill the home screen
+	 *  carries above its composer — dashed "Pick propositions from the
+	 *  map" when empty, count + Clear when picked. The draft screen has
+	 *  no graph behind it, so the picker opens the standalone chain-table
+	 *  overlay over fetched snapshot data (owned by NewSession). */
+	picks?: DraftPick[];
+	onOpenPicker?: () => void;
+	onClearPicks?: () => void;
 }) {
 	// Voice dictation (STT wave, 2026-09-17): finals append at the end of the
 	// draft text (via the parent's onChange — the truth lives there); the
@@ -144,6 +170,36 @@ export function DraftShell({
 						<div className="bg-background pb-4">
 							<div className={DOCK}>
 								{setupCta}
+								{(picks.length > 0 || mode === "practice") && (
+									<div className="mb-2 flex items-center justify-start gap-1.5">
+										<button
+											type="button"
+											data-testid="practice-props-chip"
+											onClick={onOpenPicker}
+											className={
+												"flex cursor-pointer items-center gap-1.5 rounded-full border px-3 py-1.5 font-ui text-xs transition-colors " +
+												(picks.length > 0
+													? "border-border bg-card text-foreground hover:bg-accent"
+													: "border-dashed border-border/80 bg-transparent text-muted-foreground hover:bg-accent hover:text-foreground")
+											}
+										>
+											<DumbbellIcon aria-hidden="true" className="size-3.5 text-muted-foreground" />
+											{picks.length > 0
+												? `${picks.length} ${picks.length === 1 ? "proposition" : "propositions"} selected`
+												: "Pick propositions from the map"}
+										</button>
+										{picks.length > 0 && (
+											<button
+												type="button"
+												data-testid="practice-props-clear"
+												onClick={onClearPicks}
+												className="cursor-pointer rounded-full px-2 py-1 font-ui text-xs text-muted-foreground transition-colors hover:bg-accent hover:text-foreground"
+											>
+												Clear
+											</button>
+										)}
+									</div>
+								)}
 								<div className="pointer-events-auto overflow-hidden rounded-2xl border bg-card shadow-lg">
 									<Composer
 										busy={busy}
@@ -188,6 +244,32 @@ export function NewSession({ initialConfigured, mode = "teach" }: { initialConfi
 		setText(v);
 	};
 	const [busy, setBusy] = useState(false);
+	// THE PICK BAR (owner round 10): the draft's lifted pick set + the
+	// snapshot the standalone chain-table picker reads. Lazy — the graph
+	// is fetched on FIRST open only, then reused.
+	const [picks, setPicks] = useState<DraftPick[]>([]);
+	const picksRef = useRef<DraftPick[]>([]);
+	const applyPicks = (next: DraftPick[]) => {
+		picksRef.current = next;
+		setPicks(next);
+	};
+	const [pickerOpen, setPickerOpen] = useState(false);
+	const [snapshot, setSnapshot] = useState<GraphSnapshot | null>(null);
+	const openPicker = () => {
+		if (snapshot) {
+			setPickerOpen(true);
+			return;
+		}
+		void fetch("/api/graph")
+			.then((r) => r.json() as Promise<GraphSnapshot>)
+			.then((snap) => {
+				setSnapshot(snap);
+				setPickerOpen(true);
+			})
+			.catch(() => {
+				/* an unreachable graph leaves the draft usable — pickless */
+			});
+	};
 
 	// First-run gate (model-slots wave, owner 2026-09-20): the send
 	// INTERCEPTS into the setup flow while unconfigured — no defaults for
@@ -223,7 +305,7 @@ export function NewSession({ initialConfigured, mode = "teach" }: { initialConfi
 			return;
 		}
 		setBusy(true);
-		void startDraftSession(draft, fetch, mode === "practice" ? "practice" : undefined)
+		void startDraftSession(draft, fetch, mode === "practice" ? "practice" : undefined, mode === "practice" ? picksRef.current : undefined)
 			.then((target) => {
 				if (target) router.push(target);
 				else setBusy(false);
@@ -239,6 +321,9 @@ export function NewSession({ initialConfigured, mode = "teach" }: { initialConfi
 				onChange={applyText}
 				onSend={send}
 				mode={mode}
+				picks={picks}
+				onOpenPicker={openPicker}
+				onClearPicks={() => applyPicks([])}
 				setupCta={
 					zeroKeys ? (
 						<ZeroKeysPill onOpen={() => setSetupOpen(true)} />
@@ -258,6 +343,29 @@ export function NewSession({ initialConfigured, mode = "teach" }: { initialConfi
 					)
 				}
 			/>
+			{/* THE PICKER (owner round 10): the standalone chain table over
+			    fetched snapshot data — the same select-mode overlay the home
+			    graph hosts, no graph canvas needed behind it. Controlled
+			    selection: every check/clear reports up live; Done closes. */}
+			<ChainTableOverlay
+				open={pickerOpen}
+				nodes={snapshot?.propositions ?? []}
+				chains={snapshot?.chains ?? []}
+				sessions={snapshot?.sessions ?? {}}
+				fileSources={snapshot?.fileSources ?? {}}
+				onClose={() => setPickerOpen(false)}
+				selectMode
+				controlledSelection={new Set(picks.map((p) => p.id))}
+				onSelectionChange={(ids) => {
+					const byId = new Map((snapshot?.propositions ?? []).map((n) => [n.id, n]));
+					const next: DraftPick[] = [];
+					for (const id of ids) {
+						const n = byId.get(id);
+						if (n) next.push({ id: n.id, name: n.name, statement: n.statement });
+					}
+					applyPicks(next);
+				}}
+			/>
 			{/* First-run setup: the send interception's landing surface — stage
 			    1 is the self-contained first-key screen (zero-keys wave). */}
 			<SetupDialog

tests/render-new-session.test.tsx

@@ -124,6 +124,61 @@ describe("the practice draft (?mode=practice, 2026-10-04)", () => {
 		assert.match(html, /What do you want to practice\?/);
 	});
 
+	it("THE PICK BAR (owner round 10): the practice draft carries the same pill above its composer", () => {
+		const html = renderToStaticMarkup(
+			<DraftShell
+				busy={false}
+				text=""
+				onChange={() => {}}
+				onSend={() => {}}
+				mode="practice"
+			/>,
+		);
+		assert.match(html, /Pick propositions from the map/);
+		// picked: count + Clear, the home register verbatim
+		const picked = renderToStaticMarkup(
+			<DraftShell
+				busy={false}
+				text=""
+				onChange={() => {}}
+				onSend={() => {}}
+				mode="practice"
+				picks={[{ id: "n_1", name: "Parity", statement: "Odd + odd = even." }]}
+			/>,
+		);
+		assert.match(picked, /1 proposition selected/);
+		assert.match(picked, /Clear/);
+		// teach mode with nothing picked renders nothing (home's law)
+		const teach = renderToStaticMarkup(
+			<DraftShell busy={false} text="" onChange={() => {}} onSend={() => {}} mode="teach" />,
+		);
+		assert.ok(!teach.includes("Pick propositions from the map"));
+	});
+
+	it("startDraftSession carries the picks as graphContext (the home practice contract)", async () => {
+		let body: Record<string, unknown> | null = null;
+		const f = (async (_url: string, init?: RequestInit) => {
+			body = JSON.parse(String(init?.body));
+			return new Response(JSON.stringify({ id: "c10" }), { status: 201 });
+		}) as unknown as typeof fetch;
+		await startDraftSession("drill me", f, "practice", [{ id: "n_1", name: "Parity", statement: "Odd + odd = even." }]);
+		assert.deepEqual(body, {
+			title: "drill me",
+			kind: "practice",
+			graphContext: { propositions: [{ id: "n_1", name: "Parity", statement: "Odd + odd = even." }] },
+		});
+	});
+
+	it("practice with NO picks stays lean — no graphContext key on the wire", async () => {
+		let body: Record<string, unknown> | null = null;
+		const f = (async (_url: string, init?: RequestInit) => {
+			body = JSON.parse(String(init?.body));
+			return new Response(JSON.stringify({ id: "c11" }), { status: 201 });
+		}) as unknown as typeof fetch;
+		await startDraftSession("free practice", f, "practice", []);
+		assert.deepEqual(body, { title: "free practice", kind: "practice" });
+	});
+
 	it("startDraftSession carries kind:\"practice\" to the create route", async () => {
 		let body: Record<string, unknown> | null = null;
 		const f = (async (_url: string, init?: RequestInit) => {