Feature: add stalled PR detection and reviewer ping banner

src/app/(app)/maintainer/page.tsx

@@ -1,4 +1,5 @@
 import Link from 'next/link';
+import { pingReviewers } from '@/app/actions/maintainer';
 import { redirect } from 'next/navigation';
 import { getServerSupabase } from '@/lib/supabase/server';
 import { isUserMaintainer } from '@/lib/maintainer/detect';
@@ -8,6 +9,7 @@ import {
   getMaintainerAnalyticsTrends,
   getRepoHealthOverview,
   getStaleIssues,
+  getStalePrs,
   getFlaggedAccounts,
   getTopContributors,
   getInstallationSettings,
@@ -19,6 +21,7 @@ import {
   type InstallationSettingsData,
   type RepoHealthRow,
   type StaleIssueRow,
+  type StalePrRow,
   type ContributorRow,
   type ReviewerLoadRow,
   type NoiseBreakdown,
@@ -37,6 +40,7 @@ import { VerifyButton } from '../issues/verify-button';
 import ExportCsvButton from './export-csv-button';
 import QueueSettings from './queue-settings';
 import { ResolveFlagButton } from './resolve-flag-button';
+import { StalePrBanner } from './stale-pr-banner';
 import { getContributorFunnel } from '@/app/actions/maintainer/analytics';
 import type { ContributorFunnelData } from '@/app/actions/maintainer/types';
 import { ContributorFunnel } from './contributor-funnel';
@@ -146,6 +150,8 @@ export default async function MaintainerPage({
   const reviewerLoads: ReviewerLoadRow[] = isOk(reviewerLoadsRes) ? reviewerLoadsRes.data : [];
   const maxLoad = reviewerLoads.length > 0 ? Math.max(...reviewerLoads.map((r) => r.prCount)) : 0;
 
+  const stalePrsRes = await getStalePrs({ installationId: activeInstallId });
+  const stalePrs: StalePrRow[] = isOk(stalePrsRes) ? stalePrsRes.data : [];
   let noise: NoiseBreakdown = { valid: 0, spamAi: 0, other: 0, total: 0 };
   if (settings.aiPrDetection) {
     const noiseRes = await getNoiseBreakdown({ installationId: activeInstallId });
@@ -175,6 +181,7 @@ export default async function MaintainerPage({
   return (
     <div className="min-h-screen bg-zinc-950 px-6 py-12 text-white">
       <div className="mx-auto max-w-5xl">
+        <StalePrBanner stalePrs={stalePrs} onPing={pingReviewers} />
         <header className="mb-8 flex items-baseline justify-between gap-4">
           <h1 className="font-display text-3xl font-bold">Maintainer</h1>
           <div className="flex items-center gap-2">

src/app/(app)/maintainer/stale-pr-banner.tsx

@@ -0,0 +1,104 @@
+'use client';
+
+import { useState, useTransition } from 'react';
+import { AlertCircle, X } from 'lucide-react';
+import { isOk, type Result } from '@/lib/result';
+import type { StalePrRow } from '@/app/actions/maintainer/analytics';
+
+type PingAction = (prId: number) => Promise<Result<{ commented: boolean }>>;
+
+export function StalePrBanner({
+  stalePrs,
+  onPing,
+}: {
+  stalePrs: StalePrRow[];
+  onPing: PingAction;
+}) {
+  const [dismissed, setDismissed] = useState<Set<number>>(new Set());
+  const [pinged, setPinged] = useState<Set<number>>(new Set());
+  const [errors, setErrors] = useState<Record<number, string>>({});
+  const [pending, startTransition] = useTransition();
+  const [activePingId, setActivePingId] = useState<number | null>(null);
+
+  const visible = stalePrs.filter((pr) => !dismissed.has(pr.id));
+
+  if (visible.length === 0) return null;
+
+  function dismiss(id: number) {
+    setDismissed((prev) => new Set(prev).add(id));
+  }
+
+  function handlePing(pr: StalePrRow) {
+    setActivePingId(pr.id);
+    setErrors((prev) => {
+      const next = { ...prev };
+      delete next[pr.id];
+      return next;
+    });
+    startTransition(async () => {
+      const res = await onPing(pr.id);
+      if (isOk(res)) {
+        setPinged((prev) => new Set(prev).add(pr.id));
+      } else {
+        setErrors((prev) => ({ ...prev, [pr.id]: res.error.message }));
+      }
+      setActivePingId(null);
+    });
+  }
+
+  return (
+    <div className="mb-6 space-y-2">
+      {visible.map((pr) => {
+        const hasPinged = pinged.has(pr.id);
+        const isThisPending = pending && activePingId === pr.id;
+        const error = errors[pr.id];
+
+        return (
+          <div
+            key={pr.id}
+            className="flex items-start justify-between gap-4 rounded-lg border border-amber-800/60 bg-amber-950/30 px-4 py-3"
+          >
+            <div className="flex min-w-0 items-start gap-3">
+              <AlertCircle className="mt-0.5 h-4 w-4 shrink-0 text-amber-400" />
+              <div className="min-w-0">
+                <p className="text-[13px] text-amber-100">
+                  <span className="font-mono text-amber-300">
+                    {pr.repoFullName} #{pr.number}
+                  </span>{' '}
+                  has been stalled for{' '}
+                  <span className="font-semibold text-amber-300">{pr.daysSinceUpdate} days</span>{' '}
+                  waiting on reviewer feedback.
+                </p>
+                {error && (
+                  <p className="mt-1 text-[11px] uppercase tracking-widest text-red-400">{error}</p>
+                )}
+              </div>
+            </div>
+            <div className="flex shrink-0 items-center gap-2">
+              {hasPinged ? (
+                <span className="text-[11px] uppercase tracking-widest text-emerald-400">
+                  Pinged ✓
+                </span>
+              ) : (
+                <button
+                  onClick={() => handlePing(pr)}
+                  disabled={isThisPending || pending}
+                  className="text-[11px] uppercase tracking-widest text-amber-300 underline underline-offset-2 hover:text-amber-100 disabled:cursor-not-allowed disabled:opacity-50"
+                >
+                  {isThisPending ? 'Pinging...' : 'Ping reviewers →'}
+                </button>
+              )}
+              <button
+                onClick={() => dismiss(pr.id)}
+                className="text-amber-600 hover:text-amber-300"
+                aria-label="Dismiss"
+              >
+                <X className="h-4 w-4" />
+              </button>
+            </div>
+          </div>
+        );
+      })}
+    </div>
+  );
+}

src/app/actions/maintainer/analytics.ts

@@ -125,6 +125,74 @@ export async function getStaleIssues(args: {
   );
 }
 
+export type StalePrRow = {
+  id: number;
+  number: number;
+  title: string;
+  url: string;
+  repoFullName: string;
+  daysSinceUpdate: number;
+  authorLogin: string;
+};
+
+export async function getStalePrs({
+  installationId,
+  thresholdDays = 14,
+}: {
+  installationId: number;
+  thresholdDays?: number;
+}): Promise<Result<StalePrRow[]>> {
+  const authRes = await requireMaintainer({
+    rateLimit: { namespace: 'maintainer', ...RATE_LIMIT_TIERS.STANDARD },
+    requireService: true,
+  });
+  if (!authRes.ok) return authRes;
+  const { user, service } = authRes.data;
+
+  const repos = await listMaintainerRepos(user.id, installationId);
+  if (repos.length === 0) {
+    return ok([]);
+  }
+
+  const thresholdDate = new Date();
+  thresholdDate.setDate(thresholdDate.getDate() - thresholdDays);
+
+  const { data, error } = await service
+    .from('pull_requests')
+    .select('id, number, title, url, repo_full_name, github_updated_at, author_login')
+    .in('repo_full_name', repos)
+    .eq('state', 'open')
+    .lt('github_updated_at', thresholdDate.toISOString())
+    .order('github_updated_at', { ascending: true })
+    .limit(5);
+
+  if (error) return err('db_error', error.message);
+
+  type RawStalePr = {
+    id: number;
+    number: number;
+    title: string;
+    url: string;
+    repo_full_name: string;
+    github_updated_at: string;
+    author_login: string | null;
+  };
+
+  const rows: StalePrRow[] = ((data ?? []) as RawStalePr[]).map((row) => ({
+    id: row.id,
+    number: row.number,
+    title: row.title,
+    url: row.url,
+    repoFullName: row.repo_full_name,
+    daysSinceUpdate: Math.floor(
+      (Date.now() - new Date(row.github_updated_at).getTime()) / 86_400_000,
+    ),
+    authorLogin: row.author_login ?? 'unknown',
+  }));
+
+  return ok(rows);
+}
+
 export async function getTopContributors(args: {
   installationId: number;
 }): Promise<Result<ContributorRow[]>> {
@@ -160,7 +228,7 @@ export async function getTopContributors(args: {
       .limit(5);
 
     return ok(
-      rows.map((row) => ({
+      rows.map((row: { githubHandle: string | null; xp: unknown; level: number | null }) => ({
         githubHandle: row.githubHandle ?? 'unknown',
         xp: row.xp ? Number(row.xp) : 0,
         level: row.level ?? 0,
@@ -501,12 +569,19 @@ export async function getReviewerLoad(args: {
       .orderBy(desc(count(pullRequests.id)));
 
     return ok(
-      rows.map((row) => ({
-        reviewerId: row.reviewerId as string,
-        githubHandle: row.githubHandle,
-        avatarUrl: row.avatarUrl,
-        prCount: row.prCount,
-      })),
+      rows.map(
+        (row: {
+          reviewerId: string | null;
+          githubHandle: string;
+          avatarUrl: string | null;
+          prCount: number;
+        }) => ({
+          reviewerId: row.reviewerId as string,
+          githubHandle: row.githubHandle,
+          avatarUrl: row.avatarUrl,
+          prCount: row.prCount,
+        }),
+      ),
     );
   } catch (error: any) {
     return err('query_failed', error.message || 'Drizzle query failed');