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/cross-spawn/lib/util/escape.js

@@ -0,0 +1,47 @@
+'use strict';
+
+// See http://www.robvanderwoude.com/escapechars.php
+const metaCharsRegExp = /([()\][%!^"`<>&|;, *?])/g;
+
+function escapeCommand(arg) {
+    // Escape meta chars
+    arg = arg.replace(metaCharsRegExp, '^$1');
+
+    return arg;
+}
+
+function escapeArgument(arg, doubleEscapeMetaChars) {
+    // Convert to string
+    arg = `${arg}`;
+
+    // Algorithm below is based on https://qntm.org/cmd
+    // It's slightly altered to disable JS backtracking to avoid hanging on specially crafted input
+    // Please see https://github.com/moxystudio/node-cross-spawn/pull/160 for more information
+
+    // Sequence of backslashes followed by a double quote:
+    // double up all the backslashes and escape the double quote
+    arg = arg.replace(/(?=(\\+?)?)\1"/g, '$1$1\\"');
+
+    // Sequence of backslashes followed by the end of the string
+    // (which will become a double quote later):
+    // double up all the backslashes
+    arg = arg.replace(/(?=(\\+?)?)\1$/, '$1$1');
+
+    // All other backslashes occur literally
+
+    // Quote the whole thing:
+    arg = `"${arg}"`;
+
+    // Escape meta chars
+    arg = arg.replace(metaCharsRegExp, '^$1');
+
+    // Double escape meta chars if necessary
+    if (doubleEscapeMetaChars) {
+        arg = arg.replace(metaCharsRegExp, '^$1');
+    }
+
+    return arg;
+}
+
+module.exports.command = escapeCommand;
+module.exports.argument = escapeArgument;