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/cssstyle/lib/properties/lineHeight.js

@@ -0,0 +1,26 @@
+'use strict';
+
+var TYPES = require('../parsers').TYPES;
+var valueType = require('../parsers').valueType;
+
+module.exports.isValid = function isValid(v) {
+  var type = valueType(v);
+  return (
+    (type === TYPES.KEYWORD && v.toLowerCase() === 'normal') ||
+    v.toLowerCase() === 'inherit' ||
+    type === TYPES.NUMBER ||
+    type === TYPES.LENGTH ||
+    type === TYPES.PERCENT
+  );
+};
+
+module.exports.definition = {
+  set: function(v) {
+    this._setProperty('line-height', v);
+  },
+  get: function() {
+    return this.getPropertyValue('line-height');
+  },
+  enumerable: true,
+  configurable: true,
+};