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/istanbul-reports/lib/json-summary/index.js

@@ -0,0 +1,56 @@
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+'use strict';
+const { ReportBase } = require('istanbul-lib-report');
+
+class JsonSummaryReport extends ReportBase {
+    constructor(opts) {
+        super();
+
+        this.file = opts.file || 'coverage-summary.json';
+        this.contentWriter = null;
+        this.first = true;
+    }
+
+    onStart(root, context) {
+        this.contentWriter = context.writer.writeFile(this.file);
+        this.contentWriter.write('{');
+    }
+
+    writeSummary(filePath, sc) {
+        const cw = this.contentWriter;
+        if (this.first) {
+            this.first = false;
+        } else {
+            cw.write(',');
+        }
+        cw.write(JSON.stringify(filePath));
+        cw.write(': ');
+        cw.write(JSON.stringify(sc));
+        cw.println('');
+    }
+
+    onSummary(node) {
+        if (!node.isRoot()) {
+            return;
+        }
+        this.writeSummary('total', node.getCoverageSummary());
+    }
+
+    onDetail(node) {
+        this.writeSummary(
+            node.getFileCoverage().path,
+            node.getCoverageSummary()
+        );
+    }
+
+    onEnd() {
+        const cw = this.contentWriter;
+        cw.println('}');
+        cw.close();
+    }
+}
+
+module.exports = JsonSummaryReport;