feat: ship v1.0.0 with character graph and writing analytics

Add P7 Cytoscape relationship graph with setting CRUD, P9 cockpit analytics driven by writing_sessions, chapter POV selection, and full test coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/renderer/components/cockpit/HourlyHeatmap.tsx

@@ -0,0 +1,23 @@
+interface HourlyHeatmapProps {
+  data: number[]
+  testId?: string
+}
+
+export function HourlyHeatmap({ data, testId }: HourlyHeatmapProps): React.JSX.Element {
+  const max = Math.max(...data, 1)
+  return (
+    <div className="hourly-heatmap" data-testid={testId}>
+      {data.map((value, hour) => (
+        <div
+          key={hour}
+          className="hourly-heatmap-cell"
+          title={`${hour}:00`}
+          style={{
+            opacity: value > 0 ? 0.35 + (value / max) * 0.65 : 0.2,
+            background: value > 0 ? 'var(--accent)' : undefined
+          }}
+        />
+      ))}
+    </div>
+  )
+}