Story 31: View Upcoming Stories

Add GET /workflow/upcoming endpoint that reads .story_kit/stories/upcoming/
and returns story IDs with names parsed from frontmatter. Add UpcomingPanel
component wired into Chat view with loading, error, empty, and list states.

12 new tests (3 backend, 9 frontend) all passing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/UpcomingPanel.tsx

@@ -0,0 +1,169 @@
+import type { UpcomingStory } from "../api/workflow";
+
+interface UpcomingPanelProps {
+	stories: UpcomingStory[];
+	isLoading: boolean;
+	error: string | null;
+	lastRefresh: Date | null;
+	onRefresh: () => void;
+}
+
+const formatTimestamp = (value: Date | null): string => {
+	if (!value) return "—";
+	return value.toLocaleTimeString([], {
+		hour: "2-digit",
+		minute: "2-digit",
+		second: "2-digit",
+	});
+};
+
+export function UpcomingPanel({
+	stories,
+	isLoading,
+	error,
+	lastRefresh,
+	onRefresh,
+}: UpcomingPanelProps) {
+	return (
+		<div
+			style={{
+				border: "1px solid #333",
+				borderRadius: "10px",
+				padding: "12px 16px",
+				background: "#1f1f1f",
+				display: "flex",
+				flexDirection: "column",
+				gap: "8px",
+			}}
+		>
+			<div
+				style={{
+					display: "flex",
+					alignItems: "center",
+					justifyContent: "space-between",
+					gap: "12px",
+				}}
+			>
+				<div
+					style={{
+						display: "flex",
+						alignItems: "center",
+						gap: "8px",
+					}}
+				>
+					<div style={{ fontWeight: 600 }}>Upcoming Stories</div>
+					<button
+						type="button"
+						onClick={onRefresh}
+						disabled={isLoading}
+						style={{
+							padding: "4px 10px",
+							borderRadius: "999px",
+							border: "1px solid #333",
+							background: isLoading ? "#2a2a2a" : "#2f2f2f",
+							color: isLoading ? "#777" : "#aaa",
+							cursor: isLoading ? "not-allowed" : "pointer",
+							fontSize: "0.75em",
+							fontWeight: 600,
+						}}
+					>
+						Refresh
+					</button>
+				</div>
+				<div
+					style={{
+						display: "flex",
+						flexDirection: "column",
+						alignItems: "flex-end",
+						gap: "2px",
+						fontSize: "0.85em",
+						color: "#aaa",
+					}}
+				>
+					<div>{stories.length} stories</div>
+					<div style={{ fontSize: "0.8em", color: "#777" }}>
+						Updated {formatTimestamp(lastRefresh)}
+					</div>
+				</div>
+			</div>
+
+			{isLoading ? (
+				<div style={{ fontSize: "0.85em", color: "#aaa" }}>
+					Loading upcoming stories...
+				</div>
+			) : error ? (
+				<div
+					style={{
+						fontSize: "0.85em",
+						color: "#ff7b72",
+						display: "flex",
+						alignItems: "center",
+						gap: "8px",
+						flexWrap: "wrap",
+					}}
+				>
+					<span>{error} Use Refresh to try again.</span>
+					<button
+						type="button"
+						onClick={onRefresh}
+						disabled={isLoading}
+						style={{
+							padding: "4px 10px",
+							borderRadius: "999px",
+							border: "1px solid #333",
+							background: "#2f2f2f",
+							color: "#aaa",
+							cursor: "pointer",
+							fontSize: "0.75em",
+							fontWeight: 600,
+						}}
+					>
+						Retry
+					</button>
+				</div>
+			) : stories.length === 0 ? (
+				<div style={{ fontSize: "0.85em", color: "#aaa" }}>
+					No upcoming stories.
+				</div>
+			) : (
+				<div
+					style={{
+						display: "flex",
+						flexDirection: "column",
+						gap: "6px",
+					}}
+				>
+					{stories.map((story) => (
+						<div
+							key={`upcoming-${story.story_id}`}
+							style={{
+								border: "1px solid #2a2a2a",
+								borderRadius: "8px",
+								padding: "8px 12px",
+								background: "#191919",
+								display: "flex",
+								alignItems: "center",
+								gap: "8px",
+							}}
+						>
+							<div style={{ fontWeight: 600, fontSize: "0.9em" }}>
+								{story.name ?? story.story_id}
+							</div>
+							{story.name && (
+								<div
+									style={{
+										fontSize: "0.75em",
+										color: "#777",
+										fontFamily: "monospace",
+									}}
+								>
+									{story.story_id}
+								</div>
+							)}
+						</div>
+					))}
+				</div>
+			)}
+		</div>
+	);
+}