Initial commit: DSH mind-map canvas monorepo

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

packages/shared/src/index.ts

@@ -0,0 +1,55 @@
+export * from "./types.js";
+export * from "./ops.js";
+export * from "./resolve-ops.js";
+export * from "./graph-query.js";
+
+export function now(): number {
+  return Date.now();
+}
+
+export function newId(prefix = "n"): string {
+  return `${prefix}_${crypto.randomUUID().replace(/-/g, "").slice(0, 16)}`;
+}
+
+/** Fit camera so content bbox fills a virtual viewport (server-side auto_fit). */
+export function computeFitViewport(
+  positions: Record<string, { x: number; y: number }>,
+  opts?: {
+    padding?: number;
+    viewW?: number;
+    viewH?: number;
+    nodeW?: number;
+    nodeH?: number;
+  },
+): { x: number; y: number; zoom: number } {
+  const pad = opts?.padding ?? 50;
+  const viewW = opts?.viewW ?? 1280;
+  const viewH = opts?.viewH ?? 800;
+  const nodeW = opts?.nodeW ?? 160;
+  const nodeH = opts?.nodeH ?? 44;
+  const pts = Object.values(positions);
+  if (!pts.length) return { x: 0, y: 0, zoom: 1 };
+  let minX = Infinity;
+  let maxX = -Infinity;
+  let minY = Infinity;
+  let maxY = -Infinity;
+  for (const p of pts) {
+    minX = Math.min(minX, p.x - nodeW / 2);
+    maxX = Math.max(maxX, p.x + nodeW / 2);
+    minY = Math.min(minY, p.y - nodeH / 2);
+    maxY = Math.max(maxY, p.y + nodeH / 2);
+  }
+  minX -= pad;
+  maxX += pad;
+  minY -= pad;
+  maxY += pad;
+  const bw = Math.max(40, maxX - minX);
+  const bh = Math.max(40, maxY - minY);
+  const zoom = Math.min(
+    2.5,
+    Math.max(0.12, Math.min((viewW * 0.86) / bw, (viewH * 0.86) / bh)),
+  );
+  const cx = (minX + maxX) / 2;
+  const cy = (minY + maxY) / 2;
+  return { x: -cx * zoom, y: -cy * zoom, zoom };
+}