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/d3-ease/src/poly.js

@@ -0,0 +1,37 @@
+var exponent = 3;
+
+export var polyIn = (function custom(e) {
+  e = +e;
+
+  function polyIn(t) {
+    return Math.pow(t, e);
+  }
+
+  polyIn.exponent = custom;
+
+  return polyIn;
+})(exponent);
+
+export var polyOut = (function custom(e) {
+  e = +e;
+
+  function polyOut(t) {
+    return 1 - Math.pow(1 - t, e);
+  }
+
+  polyOut.exponent = custom;
+
+  return polyOut;
+})(exponent);
+
+export var polyInOut = (function custom(e) {
+  e = +e;
+
+  function polyInOut(t) {
+    return ((t *= 2) <= 1 ? Math.pow(t, e) : 2 - Math.pow(2 - t, e)) / 2;
+  }
+
+  polyInOut.exponent = custom;
+
+  return polyInOut;
+})(exponent);