Add side panels, task selection, graph animation, and project docs

- Foldable left panel (user profile) and right panel (task details)
- Clicking a task in the list or graph node selects it and shows details
- Both views (task list + graph) always mounted via absolute inset-0 for
  correct canvas dimensions; tabs toggle visibility with opacity
- Graph node selection animation: other nodes repel outward (charge -600),
  then selected node smoothly slides to center (500ms cubic ease-out),
  then charge restores to -120 and graph stabilizes
- Graph re-fits on tab switch and panel resize via ResizeObserver
- Fix UUID string IDs throughout (backend returns UUIDs, not integers)
- Add TaskDetailPanel, UserPanel components
- Add CLAUDE.md project documentation

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

frontend/node_modules/next/dist/esm/lib/is-error.js

@@ -0,0 +1,22 @@
+import { isPlainObject } from "../shared/lib/is-plain-object";
+export default function isError(err) {
+    return typeof err === "object" && err !== null && "name" in err && "message" in err;
+}
+export function getProperError(err) {
+    if (isError(err)) {
+        return err;
+    }
+    if (process.env.NODE_ENV === "development") {
+        // provide better error for case where `throw undefined`
+        // is called in development
+        if (typeof err === "undefined") {
+            return new Error("An undefined error was thrown, " + "see here for more info: https://nextjs.org/docs/messages/threw-undefined");
+        }
+        if (err === null) {
+            return new Error("A null error was thrown, " + "see here for more info: https://nextjs.org/docs/messages/threw-undefined");
+        }
+    }
+    return new Error(isPlainObject(err) ? JSON.stringify(err) : err + "");
+}
+
+//# sourceMappingURL=is-error.js.map