feat(dashboard): message activity timeline + moderation donut

Backend:
- GET /api/dashboard/activity?days=1..90 — daily buckets (messages,
  flagged, active_users) + hourly distribution last 24h
- clamped days param, reuses existing indexes (idx_messages_created,
  ai_status_created)

Frontend:
- ActivityChart: area chart messages+flagged per day, 7/14/30d range
- HourlyActivityChart: 24h bars with peak highlight
- ModerationDonut: clean/flagged/warned/error breakdown with live
  summary line (server X% clean)
- Dashboard layout: activity 2/3 + donut 1/3, hourly + top channels

Verified: endpoint returns real data from prod DB (784/1897/8 msgs
per day), tsc clean backend+frontend.

services/backend/src/modules/dashboard/dashboard.repository.ts

@@ -82,6 +82,52 @@ export class DashboardRepository {
     };
   }
 
+  async getActivity(days: number) {
+    const db = getDatabase();
+    const sinceMs = Date.now() - days * 86400000;
+    const dayAgoMs = Date.now() - 86400000;
+
+    // Daily buckets (last N days)
+    const daily = await db.execute(sql`
+      SELECT
+        to_char(to_timestamp(created_at / 1000), 'YYYY-MM-DD') AS day,
+        COUNT(*)::int AS messages,
+        COUNT(*) FILTER (WHERE ai_status = 'flagged')::int AS flagged,
+        COUNT(DISTINCT user_id)::int AS active_users
+      FROM ${pgMessagesTable}
+      WHERE created_at >= ${sinceMs}
+      GROUP BY day
+      ORDER BY day
+    `);
+
+    // Hourly distribution (last 24h)
+    const hourly = await db.execute(sql`
+      SELECT
+        EXTRACT(HOUR FROM to_timestamp(created_at / 1000))::int AS hour,
+        COUNT(*)::int AS messages,
+        COUNT(*) FILTER (WHERE ai_status = 'flagged')::int AS flagged
+      FROM ${pgMessagesTable}
+      WHERE created_at >= ${dayAgoMs}
+      GROUP BY hour
+      ORDER BY hour
+    `);
+
+    return {
+      days,
+      daily: (daily.rows as Record<string, unknown>[]).map((r) => ({
+        day: String(r.day),
+        messages: Number(r.messages),
+        flagged: Number(r.flagged),
+        active_users: Number(r.active_users),
+      })),
+      hourly: (hourly.rows as Record<string, unknown>[]).map((r) => ({
+        hour: Number(r.hour),
+        messages: Number(r.messages),
+        flagged: Number(r.flagged),
+      })),
+    };
+  }
+
   async listUsers(query: ListUsersQuery) {
     const db = getDatabase();
     const limit = query.limit ?? 20;

services/backend/src/modules/dashboard/dashboard.routes.ts

@@ -19,6 +19,16 @@ export function createDashboardRouter(): Router {
     }),
   );
 
+  // GET /api/dashboard/activity?days=14 — message volume over time
+  router.get(
+    "/dashboard/activity",
+    asyncHandler(async (req: Request, res: Response) => {
+      const days = Math.min(Math.max(Number(req.query.days) || 14, 1), 90);
+      const activity = await dashboardService.getActivity(days);
+      res.json(activity);
+    }),
+  );
+
   // GET /api/dashboard/users — paginated user list with profiles
   router.get(
     "/dashboard/users",

services/backend/src/modules/dashboard/dashboard.service.ts

@@ -15,6 +15,11 @@ export class DashboardService {
     return dashboardRepository.getStats();
   }
 
+  async getActivity(days: number) {
+    logger.debug({ days }, "Fetching dashboard activity");
+    return dashboardRepository.getActivity(days);
+  }
+
   async listUsers(query: ListUsersQuery) {
     logger.debug({ query }, "Listing dashboard users");
     return dashboardRepository.listUsers(query);

services/frontend/src/app/(dashboard)/dashboard/page.tsx

@@ -9,19 +9,34 @@ import {
   Users,
 } from "lucide-react";
 import { useState } from "react";
+import { ActivityChart } from "@/components/dashboard/activity-chart";
 import { ChannelsSection } from "@/components/dashboard/channels-section";
+import { HourlyActivityChart } from "@/components/dashboard/hourly-activity-chart";
+import { ModerationDonut } from "@/components/dashboard/moderation-donut";
 import { StatCard } from "@/components/dashboard/stat-card";
 import { TopChannelsChart } from "@/components/dashboard/top-channels-chart";
 import { UsersSection } from "@/components/dashboard/users-section";
 import { SubNav } from "@/components/layout/sub-nav";
 import { ErrorState, LoadingSkeleton } from "@/components/shared";
-import { useStats } from "@/hooks";
+import { useActivity, useStats } from "@/hooks";
+import { cn } from "@/lib/utils";
 
 type DashboardTab = "stats" | "users" | "channels";
 
+const DAY_RANGES = [7, 14, 30] as const;
+
+const MODERATION_COLORS: Record<string, string> = {
+  Clean: "oklch(0.72 0.16 155)",
+  Flagged: "oklch(0.62 0.19 25)",
+  Warned: "oklch(0.78 0.15 80)",
+  Error: "oklch(0.55 0.02 245)",
+};
+
 export default function DashboardPage() {
   const [tab, setTab] = useState<DashboardTab>("stats");
+  const [days, setDays] = useState<number>(14);
   const { data: stats, isLoading, error, mutate: refetch } = useStats();
+  const { data: activity, isLoading: activityLoading } = useActivity(days);
 
   const subNavTabs = [
     { id: "stats", label: "Stats", icon: <Hash className="size-3" /> },
@@ -29,6 +44,31 @@ export default function DashboardPage() {
     { id: "channels", label: "Channels", icon: <Hash className="size-3" /> },
   ];
 
+  const moderationData = stats
+    ? [
+        {
+          name: "Clean",
+          value: stats.total_clean,
+          color: MODERATION_COLORS.Clean,
+        },
+        {
+          name: "Flagged",
+          value: stats.total_flagged,
+          color: MODERATION_COLORS.Flagged,
+        },
+        {
+          name: "Warned",
+          value: stats.total_warned,
+          color: MODERATION_COLORS.Warned,
+        },
+        {
+          name: "Error",
+          value: stats.total_error,
+          color: MODERATION_COLORS.Error,
+        },
+      ].filter((d) => d.value > 0)
+    : [];
+
   return (
     <div className="space-y-4 animate-fade-in-up">
       <SubNav
@@ -80,12 +120,50 @@ export default function DashboardPage() {
                 />
               </div>
 
-              <TopChannelsChart
+              <div className="flex items-center justify-end gap-1">
-                data={stats.top_channels.map((c) => ({
+                {DAY_RANGES.map((range) => (
-                  name: c.channel_name ?? c.channel_id,
+                  <button
-                  count: c.message_count,
+                    key={range}
-                }))}
+                    type="button"
-              />
+                    onClick={() => setDays(range)}
+                    className={cn(
+                      "px-2.5 py-1 text-[10px] font-medium uppercase tracking-wide rounded-md transition-colors",
+                      days === range
+                        ? "bg-primary/20 text-primary"
+                        : "text-text-secondary/60 hover:text-text-primary",
+                    )}
+                  >
+                    {range}d
+                  </button>
+                ))}
+              </div>
+
+              <div className="grid grid-cols-1 gap-4 xl:grid-cols-3">
+                <div className="xl:col-span-2">
+                  {activityLoading ? (
+                    <LoadingSkeleton count={1} height="h-56" />
+                  ) : (
+                    <ActivityChart data={activity?.daily} />
+                  )}
+                </div>
+                <ModerationDonut data={moderationData} />
+              </div>
+
+              <div className="grid grid-cols-1 gap-4 xl:grid-cols-3">
+                <div className="xl:col-span-2">
+                  {activityLoading ? (
+                    <LoadingSkeleton count={1} height="h-40" />
+                  ) : (
+                    <HourlyActivityChart data={activity?.hourly} />
+                  )}
+                </div>
+                <TopChannelsChart
+                  data={stats.top_channels.map((c) => ({
+                    name: c.channel_name ?? c.channel_id,
+                    count: c.message_count,
+                  }))}
+                />
+              </div>
             </>
           )}
         </div>

services/frontend/src/components/dashboard/activity-chart.tsx

@@ -0,0 +1,128 @@
+"use client";
+
+import {
+  Area,
+  AreaChart,
+  CartesianGrid,
+  ResponsiveContainer,
+  Tooltip,
+  XAxis,
+  YAxis,
+} from "recharts";
+import { GlassCard } from "@/components/glass/card";
+import { useMounted } from "@/lib/hooks/use-mounted";
+
+interface ActivityChartProps {
+  data?: { day: string; messages: number; flagged: number }[];
+}
+
+const TOOLTIP_STYLE = {
+  background: "oklch(0.11 0.02 245 / 0.95)",
+  border: "1px solid oklch(1 0 0 / 0.08)",
+  borderRadius: 8,
+  fontSize: 12,
+  color: "oklch(0.93 0.01 245)",
+} as const;
+
+export function ActivityChart({ data = [] }: ActivityChartProps) {
+  const mounted = useMounted();
+
+  return (
+    <GlassCard variant="base">
+      <div className="flex items-center justify-between mb-3">
+        <span className="text-xs font-semibold tracking-wide uppercase text-text-secondary">
+          Message Activity
+        </span>
+        <span className="text-[10px] text-text-secondary/50">
+          messages · flagged per day
+        </span>
+      </div>
+      <div className="h-56">
+        {mounted ? (
+          <ResponsiveContainer
+            width="100%"
+            height="100%"
+            minWidth={0}
+            minHeight={0}
+          >
+            <AreaChart data={data} margin={{ left: -18, right: 4, top: 4 }}>
+              <defs>
+                <linearGradient id="gradMessages" x1="0" y1="0" x2="0" y2="1">
+                  <stop
+                    offset="0%"
+                    stopColor="var(--color-primary)"
+                    stopOpacity={0.45}
+                  />
+                  <stop
+                    offset="100%"
+                    stopColor="var(--color-primary)"
+                    stopOpacity={0.02}
+                  />
+                </linearGradient>
+                <linearGradient id="gradFlagged" x1="0" y1="0" x2="0" y2="1">
+                  <stop
+                    offset="0%"
+                    stopColor="oklch(0.62 0.19 25)"
+                    stopOpacity={0.5}
+                  />
+                  <stop
+                    offset="100%"
+                    stopColor="oklch(0.62 0.19 25)"
+                    stopOpacity={0.02}
+                  />
+                </linearGradient>
+              </defs>
+              <CartesianGrid
+                strokeDasharray="3 3"
+                stroke="oklch(1 0 0 / 0.05)"
+                vertical={false}
+              />
+              <XAxis
+                dataKey="day"
+                axisLine={false}
+                tickLine={false}
+                tick={{ fill: "oklch(0.55 0.02 245)", fontSize: 10 }}
+                tickFormatter={(v: string) => {
+                  const [, m, d] = v.split("-");
+                  return `${Number(m)}/${Number(d)}`;
+                }}
+                minTickGap={24}
+              />
+              <YAxis
+                axisLine={false}
+                tickLine={false}
+                tick={{ fill: "oklch(0.55 0.02 245)", fontSize: 10 }}
+                allowDecimals={false}
+              />
+              <Tooltip
+                contentStyle={TOOLTIP_STYLE}
+                labelFormatter={(label) => {
+                  const [y, m, d] = String(label).split("-");
+                  return `${d}/${m}/${y}`;
+                }}
+              />
+              <Area
+                type="monotone"
+                dataKey="messages"
+                stroke="var(--color-primary)"
+                strokeWidth={2}
+                fill="url(#gradMessages)"
+                name="Messages"
+              />
+              <Area
+                type="monotone"
+                dataKey="flagged"
+                stroke="oklch(0.62 0.19 25)"
+                strokeWidth={2}
+                fill="url(#gradFlagged)"
+                name="Flagged"
+              />
+            </AreaChart>
+          </ResponsiveContainer>
+        ) : (
+          <div className="h-full w-full animate-pulse rounded-md bg-card/40" />
+        )}
+      </div>
+    </GlassCard>
+  );
+}

services/frontend/src/components/dashboard/hourly-activity-chart.tsx

@@ -0,0 +1,108 @@
+"use client";
+
+import {
+  Bar,
+  BarChart,
+  Cell,
+  ResponsiveContainer,
+  Tooltip,
+  XAxis,
+  YAxis,
+} from "recharts";
+import { GlassCard } from "@/components/glass/card";
+import { useMounted } from "@/lib/hooks/use-mounted";
+
+interface HourlyActivityChartProps {
+  data?: { hour: number; messages: number; flagged: number }[];
+}
+
+const HOUR_LABELS = Array.from({ length: 24 }, (_, i) => {
+  const h = i % 12 === 0 ? 12 : i % 12;
+  return `${h}${i < 12 ? "am" : "pm"}`;
+});
+
+const TOOLTIP_STYLE = {
+  background: "oklch(0.11 0.02 245 / 0.95)",
+  border: "1px solid oklch(1 0 0 / 0.08)",
+  borderRadius: 8,
+  fontSize: 12,
+  color: "oklch(0.93 0.01 245)",
+} as const;
+
+export function HourlyActivityChart({ data = [] }: HourlyActivityChartProps) {
+  const mounted = useMounted();
+
+  const full = Array.from({ length: 24 }, (_, hour) => {
+    const found = data.find((d) => d.hour === hour);
+    return {
+      hour,
+      label: HOUR_LABELS[hour],
+      messages: found?.messages ?? 0,
+      flagged: found?.flagged ?? 0,
+    };
+  });
+
+  const peak = Math.max(1, ...full.map((d) => d.messages));
+  const maxMessages = Math.max(...full.map((d) => d.messages));
+
+  return (
+    <GlassCard variant="base">
+      <div className="flex items-center justify-between mb-3">
+        <span className="text-xs font-semibold tracking-wide uppercase text-text-secondary">
+          Hourly Activity
+        </span>
+        <span className="text-[10px] text-text-secondary/50">
+          last 24h · peak {maxMessages} msgs
+        </span>
+      </div>
+      <div className="h-40">
+        {mounted ? (
+          <ResponsiveContainer
+            width="100%"
+            height="100%"
+            minWidth={0}
+            minHeight={0}
+          >
+            <BarChart data={full} margin={{ left: -22, right: 4, top: 4 }}>
+              <XAxis
+                dataKey="label"
+                axisLine={false}
+                tickLine={false}
+                tick={{ fill: "oklch(0.55 0.02 245)", fontSize: 9 }}
+                interval={3}
+              />
+              <YAxis
+                axisLine={false}
+                tickLine={false}
+                tick={{ fill: "oklch(0.55 0.02 245)", fontSize: 10 }}
+                allowDecimals={false}
+                domain={[0, (dataMax: number) => Math.max(1, dataMax)]}
+              />
+              <Tooltip
+                contentStyle={TOOLTIP_STYLE}
+                cursor={{ fill: "oklch(1 0 0 / 0.04)" }}
+                labelFormatter={(label) => `Hour ${label}`}
+              />
+              <Bar dataKey="messages" radius={[3, 3, 0, 0]} name="Messages">
+                {full.map((d) => (
+                  <Cell
+                    key={d.hour}
+                    fill={
+                      d.messages === maxMessages && maxMessages > 0
+                        ? "var(--color-primary)"
+                        : d.messages > peak * 0.5
+                          ? "oklch(0.52 0.13 245 / 0.7)"
+                          : "oklch(0.52 0.13 245 / 0.35)"
+                    }
+                  />
+                ))}
+              </Bar>
+            </BarChart>
+          </ResponsiveContainer>
+        ) : (
+          <div className="h-full w-full animate-pulse rounded-md bg-card/40" />
+        )}
+      </div>
+    </GlassCard>
+  );
+}

services/frontend/src/components/dashboard/moderation-donut.tsx

@@ -0,0 +1,101 @@
+"use client";
+
+import { Cell, Pie, PieChart, ResponsiveContainer, Tooltip } from "recharts";
+import { GlassCard } from "@/components/glass/card";
+import { useMounted } from "@/lib/hooks/use-mounted";
+
+interface ModerationDonutProps {
+  data?: { name: string; value: number; color: string }[];
+}
+
+const TOOLTIP_STYLE = {
+  background: "oklch(0.11 0.02 245 / 0.95)",
+  border: "1px solid oklch(1 0 0 / 0.08)",
+  borderRadius: 8,
+  fontSize: 12,
+  color: "oklch(0.93 0.01 245)",
+} as const;
+
+export function ModerationDonut({ data = [] }: ModerationDonutProps) {
+  const mounted = useMounted();
+  const total = data.reduce((sum, d) => sum + d.value, 0);
+  const cleanPct =
+    total > 0
+      ? Math.round(
+          ((data.find((d) => d.name === "Clean")?.value ?? 0) / total) * 100,
+        )
+      : 0;
+
+  return (
+    <GlassCard variant="base">
+      <div className="flex items-center justify-between mb-1">
+        <span className="text-xs font-semibold tracking-wide uppercase text-text-secondary">
+          Moderation Breakdown
+        </span>
+      </div>
+      <div className="flex items-center gap-4">
+        <div className="relative h-40 w-40 shrink-0">
+          {mounted ? (
+            <ResponsiveContainer width="100%" height="100%">
+              <PieChart>
+                <Pie
+                  data={data}
+                  dataKey="value"
+                  nameKey="name"
+                  innerRadius={52}
+                  outerRadius={72}
+                  paddingAngle={2}
+                  strokeWidth={0}
+                >
+                  {data.map((entry) => (
+                    <Cell key={entry.name} fill={entry.color} />
+                  ))}
+                </Pie>
+                <Tooltip contentStyle={TOOLTIP_STYLE} />
+              </PieChart>
+            </ResponsiveContainer>
+          ) : (
+            <div className="h-full w-full animate-pulse rounded-full bg-card/40" />
+          )}
+          <div className="absolute inset-0 flex flex-col items-center justify-center pointer-events-none">
+            <span className="text-2xl font-bold text-text-primary">
+              {total.toLocaleString()}
+            </span>
+            <span className="text-[10px] uppercase tracking-wide text-text-secondary/60">
+              messages
+            </span>
+          </div>
+        </div>
+
+        <div className="min-w-0 flex-1 space-y-1.5">
+          {data.map((d) => (
+            <div key={d.name} className="flex items-center gap-2 text-xs">
+              <span
+                className="size-2.5 shrink-0 rounded-sm"
+                style={{ background: d.color }}
+              />
+              <span className="text-text-secondary">{d.name}</span>
+              <span className="ml-auto font-mono text-text-primary">
+                {d.value.toLocaleString()}
+              </span>
+              <span className="w-10 text-right font-mono text-text-secondary/50">
+                {total > 0 ? Math.round((d.value / total) * 100) : 0}%
+              </span>
+            </div>
+          ))}
+          {cleanPct >= 90 && (
+            <p className="pt-1 text-[10px] text-green-500/80">
+              ✓ Server is {cleanPct}% clean — moderation is holding up well
+            </p>
+          )}
+          {cleanPct < 90 && cleanPct > 0 && (
+            <p className="pt-1 text-[10px] text-amber-500/80">
+              {100 - cleanPct}% of messages were flagged or warned — review
+              activity in the Analysis tab
+            </p>
+          )}
+        </div>
+      </div>
+    </GlassCard>
+  );
+}

services/frontend/src/hooks/index.ts

@@ -1,5 +1,6 @@
 export { useConfig } from "./use-config";
 export {
+  useActivity,
   useChannelDetail,
   useChannels,
   useStats,

services/frontend/src/hooks/use-dashboard.ts

@@ -2,6 +2,7 @@ import useSWR from "swr";
 
 import { dashboardApi } from "@/lib/api";
 import type {
+  DashboardActivity,
   DashboardChannelDetail,
   DashboardStats,
   DashboardUserDetail,
@@ -13,6 +14,12 @@ export function useStats() {
   );
 }
 
+export function useActivity(days = 14) {
+  return useSWR<DashboardActivity>(["dashboard-activity", days], () =>
+    dashboardApi.getActivity(days),
+  );
+}
+
 export function useUsers(search?: string) {
   return useSWR(
     ["dashboard-users", search ?? ""],

services/frontend/src/lib/api/dashboard.ts

@@ -1,4 +1,5 @@
 import type {
+  DashboardActivity,
   DashboardChannelDetail,
   DashboardStats,
   DashboardUserDetail,
@@ -10,6 +11,9 @@ import { api } from "./client";
 export const dashboardApi = {
   getStats: () => api.get<DashboardStats>("/api/dashboard/stats"),
 
+  getActivity: (days = 14) =>
+    api.get<DashboardActivity>(`/api/dashboard/activity?days=${days}`),
+
   listUsers: (limit?: number, cursor?: string, search?: string) => {
     const params = new URLSearchParams();
     if (limit) params.set("limit", String(limit));

services/frontend/src/lib/types/dashboard.ts

@@ -28,6 +28,25 @@ export interface ModerationOverview {
   error: number;
 }
 
+export interface DashboardActivity {
+  days: number;
+  daily: DailyActivityPoint[];
+  hourly: HourlyActivityPoint[];
+}
+
+export interface DailyActivityPoint {
+  day: string; // YYYY-MM-DD
+  messages: number;
+  flagged: number;
+  active_users: number;
+}
+
+export interface HourlyActivityPoint {
+  hour: number; // 0-23
+  messages: number;
+  flagged: number;
+}
+
 export interface DashboardUser {
   user_id: string;
   username?: string | null;