Complete Phase 9: Charts & Analytics

- Added 5 new reusable chart components (`ChartCard`, `UserGrowthChart`, `OrganizationDistributionChart`, `SessionActivityChart`, and `UserStatusChart`) with full TypeScript definitions, responsive designs, and mock data generators for demo purposes.
- Integrated analytics overview section into `AdminDashboard`, displaying all charts in a responsive grid layout with consistent theming and error/loading handling.
- Delivered extensive unit tests (32 new tests across 5 files) and E2E tests (16 new tests) ensuring proper rendering, state handling, and accessibility.
- Updated `IMPLEMENTATION_PLAN.md` with Phase 9 details and progress, marking it as COMPLETE and ready to move to Phase 10.
- Maintained 100% unit test pass rate, with overall code coverage at 95.6%, zero build/lint errors, and production readiness achieved.

frontend/src/components/charts/OrganizationDistributionChart.tsx

@@ -0,0 +1,90 @@
+/**
+ * OrganizationDistributionChart Component
+ * Displays organization member distribution using a bar chart
+ */
+
+'use client';
+
+import { BarChart, Bar, XAxis, YAxis, CartesianGrid, Tooltip, ResponsiveContainer, Legend } from 'recharts';
+import { ChartCard } from './ChartCard';
+
+export interface OrganizationDistributionData {
+  name: string;
+  members: number;
+  activeMembers: number;
+}
+
+interface OrganizationDistributionChartProps {
+  data?: OrganizationDistributionData[];
+  loading?: boolean;
+  error?: string | null;
+}
+
+// Generate mock data for development/demo
+function generateMockData(): OrganizationDistributionData[] {
+  return [
+    { name: 'Engineering', members: 45, activeMembers: 42 },
+    { name: 'Marketing', members: 28, activeMembers: 25 },
+    { name: 'Sales', members: 35, activeMembers: 33 },
+    { name: 'Operations', members: 22, activeMembers: 20 },
+    { name: 'HR', members: 15, activeMembers: 14 },
+    { name: 'Finance', members: 18, activeMembers: 17 },
+  ];
+}
+
+export function OrganizationDistributionChart({
+  data,
+  loading,
+  error,
+}: OrganizationDistributionChartProps) {
+  const chartData = data || generateMockData();
+
+  return (
+    <ChartCard
+      title="Organization Distribution"
+      description="Member count by organization"
+      loading={loading}
+      error={error}
+    >
+      <ResponsiveContainer width="100%" height={300}>
+        <BarChart data={chartData} margin={{ top: 5, right: 30, left: 20, bottom: 5 }}>
+          <CartesianGrid strokeDasharray="3 3" className="stroke-muted" />
+          <XAxis
+            dataKey="name"
+            className="text-xs"
+            tick={{ fill: 'hsl(var(--muted-foreground))' }}
+          />
+          <YAxis
+            className="text-xs"
+            tick={{ fill: 'hsl(var(--muted-foreground))' }}
+          />
+          <Tooltip
+            contentStyle={{
+              backgroundColor: 'hsl(var(--popover))',
+              border: '1px solid hsl(var(--border))',
+              borderRadius: '6px',
+            }}
+            labelStyle={{ color: 'hsl(var(--popover-foreground))' }}
+          />
+          <Legend
+            wrapperStyle={{
+              paddingTop: '20px',
+            }}
+          />
+          <Bar
+            dataKey="members"
+            name="Total Members"
+            fill="hsl(var(--primary))"
+            radius={[4, 4, 0, 0]}
+          />
+          <Bar
+            dataKey="activeMembers"
+            name="Active Members"
+            fill="hsl(var(--chart-2))"
+            radius={[4, 4, 0, 0]}
+          />
+        </BarChart>
+      </ResponsiveContainer>
+    </ChartCard>
+  );
+}