Implement 15 platform features: digest, availability, templates, comparison, live voting SSE, file versioning, mentorship, messaging, analytics, drafts, webhooks, peer review, audit enhancements, i18n

Features implemented:
- F1: Email digest notifications with cron endpoint and per-user frequency
- F2: Jury availability windows and workload preferences in smart assignment
- F3: Round templates with save-from-round and CRUD management
- F4: Side-by-side project comparison view for jury members
- F5: Real-time voting dashboard with Server-Sent Events (SSE)
- F6: Live voting UX: QR codes, audience voting, tie-breaking, score animations
- F7: File versioning, inline preview, bulk download with presigned URLs
- F8: Mentor dashboard: milestones, private notes, activity tracking
- F9: Communication hub with broadcasts, templates, and recipient targeting
- F10: Advanced analytics: cross-round comparison, juror consistency, diversity metrics, PDF export
- F11: Applicant draft saving with magic link resume and cron cleanup
- F12: Webhook integration layer with HMAC signing, retry, and delivery logs
- F13: Peer review discussions with anonymized scores and threaded comments
- F14: Audit log enhancements: before/after diffs, session grouping, anomaly detection, retention
- F15: i18n foundation with next-intl (EN/FR), cookie-based locale, language switcher

Schema: 12 new models, field additions to User, Project, ProjectFile, LiveVotingSession, LiveVote, MentorAssignment, AuditLog, Program
New routers: roundTemplate, message, webhook (registered in _app.ts)
New services: email-digest, webhook-dispatcher
New cron endpoints: /api/cron/digest, /api/cron/draft-cleanup, /api/cron/audit-cleanup
New API routes: /api/live-voting/stream (SSE), /api/files/bulk-download

All features are admin-configurable via SystemSettings or per-model settingsJson fields.
Docker build verified successfully.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/settings/settings-content.tsx

@@ -20,6 +20,12 @@ import {
   Bell,
   Tags,
   ExternalLink,
+  Newspaper,
+  BarChart3,
+  ShieldAlert,
+  Globe,
+  Webhook,
+  LayoutTemplate,
 } from 'lucide-react'
 import Link from 'next/link'
 import { Button } from '@/components/ui/button'
@@ -112,9 +118,42 @@ export function SettingsContent({ initialSettings }: SettingsContentProps) {
     'autosave_interval_seconds',
   ])
 
+  const digestSettings = getSettingsByKeys([
+    'digest_enabled',
+    'digest_default_frequency',
+    'digest_send_hour',
+    'digest_include_evaluations',
+    'digest_include_assignments',
+    'digest_include_deadlines',
+    'digest_include_announcements',
+  ])
+
+  const analyticsSettings = getSettingsByKeys([
+    'analytics_observer_scores_tab',
+    'analytics_observer_progress_tab',
+    'analytics_observer_juror_tab',
+    'analytics_observer_comparison_tab',
+    'analytics_pdf_enabled',
+    'analytics_pdf_sections',
+  ])
+
+  const auditSecuritySettings = getSettingsByKeys([
+    'audit_retention_days',
+    'anomaly_detection_enabled',
+    'anomaly_rapid_actions_threshold',
+    'anomaly_off_hours_start',
+    'anomaly_off_hours_end',
+  ])
+
+  const localizationSettings = getSettingsByKeys([
+    'localization_enabled_locales',
+    'localization_default_locale',
+  ])
+
   return (
+    <>
     <Tabs defaultValue="ai" className="space-y-6">
-      <TabsList className="grid w-full grid-cols-4 lg:grid-cols-8">
+      <TabsList className="flex flex-wrap h-auto gap-1">
         <TabsTrigger value="ai" className="gap-2">
           <Bot className="h-4 w-4" />
           <span className="hidden sm:inline">AI</span>
@@ -147,6 +186,22 @@ export function SettingsContent({ initialSettings }: SettingsContentProps) {
           <SettingsIcon className="h-4 w-4" />
           <span className="hidden sm:inline">Defaults</span>
         </TabsTrigger>
+        <TabsTrigger value="digest" className="gap-2">
+          <Newspaper className="h-4 w-4" />
+          <span className="hidden sm:inline">Digest</span>
+        </TabsTrigger>
+        <TabsTrigger value="analytics" className="gap-2">
+          <BarChart3 className="h-4 w-4" />
+          <span className="hidden sm:inline">Analytics</span>
+        </TabsTrigger>
+        <TabsTrigger value="audit" className="gap-2">
+          <ShieldAlert className="h-4 w-4" />
+          <span className="hidden sm:inline">Audit</span>
+        </TabsTrigger>
+        <TabsTrigger value="localization" className="gap-2">
+          <Globe className="h-4 w-4" />
+          <span className="hidden sm:inline">Locale</span>
+        </TabsTrigger>
       </TabsList>
 
       <TabsContent value="ai" className="space-y-6">
@@ -279,8 +334,456 @@ export function SettingsContent({ initialSettings }: SettingsContentProps) {
           </CardContent>
         </Card>
       </TabsContent>
+
+      <TabsContent value="digest" className="space-y-6">
+        <Card>
+          <CardHeader>
+            <CardTitle>Digest Configuration</CardTitle>
+            <CardDescription>
+              Configure automated digest emails sent to users
+            </CardDescription>
+          </CardHeader>
+          <CardContent>
+            <DigestSettingsSection settings={digestSettings} />
+          </CardContent>
+        </Card>
+      </TabsContent>
+
+      <TabsContent value="analytics" className="space-y-6">
+        <Card>
+          <CardHeader>
+            <CardTitle>Analytics & Reports</CardTitle>
+            <CardDescription>
+              Configure observer dashboard visibility and PDF report settings
+            </CardDescription>
+          </CardHeader>
+          <CardContent>
+            <AnalyticsSettingsSection settings={analyticsSettings} />
+          </CardContent>
+        </Card>
+      </TabsContent>
+
+      <TabsContent value="audit" className="space-y-6">
+        <Card>
+          <CardHeader>
+            <CardTitle>Audit & Security</CardTitle>
+            <CardDescription>
+              Configure audit log retention and anomaly detection
+            </CardDescription>
+          </CardHeader>
+          <CardContent>
+            <AuditSettingsSection settings={auditSecuritySettings} />
+          </CardContent>
+        </Card>
+      </TabsContent>
+
+      <TabsContent value="localization" className="space-y-6">
+        <Card>
+          <CardHeader>
+            <CardTitle>Localization</CardTitle>
+            <CardDescription>
+              Configure language and locale settings
+            </CardDescription>
+          </CardHeader>
+          <CardContent>
+            <LocalizationSettingsSection settings={localizationSettings} />
+          </CardContent>
+        </Card>
+      </TabsContent>
     </Tabs>
+
+    {/* Quick Links to sub-pages */}
+    <div className="grid gap-4 sm:grid-cols-2">
+      <Card>
+        <CardHeader>
+          <CardTitle className="text-base flex items-center gap-2">
+            <LayoutTemplate className="h-4 w-4" />
+            Round Templates
+          </CardTitle>
+          <CardDescription>
+            Create reusable round configuration templates
+          </CardDescription>
+        </CardHeader>
+        <CardContent>
+          <Button asChild>
+            <Link href="/admin/settings/templates">
+              <LayoutTemplate className="mr-2 h-4 w-4" />
+              Manage Templates
+              <ExternalLink className="ml-2 h-3 w-3" />
+            </Link>
+          </Button>
+        </CardContent>
+      </Card>
+
+      <Card>
+        <CardHeader>
+          <CardTitle className="text-base flex items-center gap-2">
+            <Webhook className="h-4 w-4" />
+            Webhooks
+          </CardTitle>
+          <CardDescription>
+            Configure webhook endpoints for platform events
+          </CardDescription>
+        </CardHeader>
+        <CardContent>
+          <Button asChild>
+            <Link href="/admin/settings/webhooks">
+              <Webhook className="mr-2 h-4 w-4" />
+              Manage Webhooks
+              <ExternalLink className="ml-2 h-3 w-3" />
+            </Link>
+          </Button>
+        </CardContent>
+      </Card>
+    </div>
+    </>
   )
 }
 
 export { SettingsSkeleton }
+
+// Inline settings sections for new tabs
+
+import { useState } from 'react'
+import { Switch } from '@/components/ui/switch'
+import { Input } from '@/components/ui/input'
+import { Label } from '@/components/ui/label'
+import { Checkbox } from '@/components/ui/checkbox'
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from '@/components/ui/select'
+import { Loader2 } from 'lucide-react'
+import { toast } from 'sonner'
+
+function useSettingsMutation() {
+  const utils = trpc.useUtils()
+  return trpc.settings.update.useMutation({
+    onSuccess: () => {
+      utils.settings.invalidate()
+      toast.success('Setting updated')
+    },
+    onError: (e) => toast.error(e.message),
+  })
+}
+
+function SettingToggle({
+  label,
+  description,
+  settingKey,
+  value,
+}: {
+  label: string
+  description?: string
+  settingKey: string
+  value: string
+}) {
+  const mutation = useSettingsMutation()
+  const isChecked = value === 'true'
+
+  return (
+    <div className="flex items-center justify-between rounded-lg border p-3">
+      <div className="space-y-0.5">
+        <Label className="text-sm font-medium">{label}</Label>
+        {description && (
+          <p className="text-xs text-muted-foreground">{description}</p>
+        )}
+      </div>
+      <Switch
+        checked={isChecked}
+        disabled={mutation.isPending}
+        onCheckedChange={(checked) =>
+          mutation.mutate({ key: settingKey, value: String(checked) })
+        }
+      />
+    </div>
+  )
+}
+
+function SettingInput({
+  label,
+  description,
+  settingKey,
+  value,
+  type = 'text',
+}: {
+  label: string
+  description?: string
+  settingKey: string
+  value: string
+  type?: string
+}) {
+  const [localValue, setLocalValue] = useState(value)
+  const mutation = useSettingsMutation()
+
+  const save = () => {
+    if (localValue !== value) {
+      mutation.mutate({ key: settingKey, value: localValue })
+    }
+  }
+
+  return (
+    <div className="space-y-2">
+      <Label className="text-sm font-medium">{label}</Label>
+      {description && (
+        <p className="text-xs text-muted-foreground">{description}</p>
+      )}
+      <div className="flex gap-2">
+        <Input
+          type={type}
+          value={localValue}
+          onChange={(e) => setLocalValue(e.target.value)}
+          onBlur={save}
+          className="max-w-xs"
+        />
+        {mutation.isPending && <Loader2 className="h-4 w-4 animate-spin self-center" />}
+      </div>
+    </div>
+  )
+}
+
+function SettingSelect({
+  label,
+  description,
+  settingKey,
+  value,
+  options,
+}: {
+  label: string
+  description?: string
+  settingKey: string
+  value: string
+  options: Array<{ value: string; label: string }>
+}) {
+  const mutation = useSettingsMutation()
+
+  return (
+    <div className="space-y-2">
+      <Label className="text-sm font-medium">{label}</Label>
+      {description && (
+        <p className="text-xs text-muted-foreground">{description}</p>
+      )}
+      <Select
+        value={value || options[0]?.value}
+        onValueChange={(v) => mutation.mutate({ key: settingKey, value: v })}
+        disabled={mutation.isPending}
+      >
+        <SelectTrigger className="max-w-xs">
+          <SelectValue />
+        </SelectTrigger>
+        <SelectContent>
+          {options.map((opt) => (
+            <SelectItem key={opt.value} value={opt.value}>
+              {opt.label}
+            </SelectItem>
+          ))}
+        </SelectContent>
+      </Select>
+    </div>
+  )
+}
+
+function DigestSettingsSection({ settings }: { settings: Record<string, string> }) {
+  return (
+    <div className="space-y-4">
+      <SettingToggle
+        label="Enable Digest Emails"
+        description="Send periodic digest emails summarizing platform activity"
+        settingKey="digest_enabled"
+        value={settings.digest_enabled || 'false'}
+      />
+      <SettingSelect
+        label="Default Frequency"
+        description="How often digests are sent to users by default"
+        settingKey="digest_default_frequency"
+        value={settings.digest_default_frequency || 'weekly'}
+        options={[
+          { value: 'daily', label: 'Daily' },
+          { value: 'weekly', label: 'Weekly' },
+          { value: 'biweekly', label: 'Bi-weekly' },
+          { value: 'monthly', label: 'Monthly' },
+        ]}
+      />
+      <SettingInput
+        label="Send Hour (UTC)"
+        description="Hour of day when digest emails are sent (0-23)"
+        settingKey="digest_send_hour"
+        value={settings.digest_send_hour || '8'}
+        type="number"
+      />
+      <div className="border-t pt-4 space-y-3">
+        <Label className="text-sm font-medium">Digest Sections</Label>
+        <SettingToggle
+          label="Include Evaluations"
+          settingKey="digest_include_evaluations"
+          value={settings.digest_include_evaluations || 'true'}
+        />
+        <SettingToggle
+          label="Include Assignments"
+          settingKey="digest_include_assignments"
+          value={settings.digest_include_assignments || 'true'}
+        />
+        <SettingToggle
+          label="Include Deadlines"
+          settingKey="digest_include_deadlines"
+          value={settings.digest_include_deadlines || 'true'}
+        />
+        <SettingToggle
+          label="Include Announcements"
+          settingKey="digest_include_announcements"
+          value={settings.digest_include_announcements || 'true'}
+        />
+      </div>
+    </div>
+  )
+}
+
+function AnalyticsSettingsSection({ settings }: { settings: Record<string, string> }) {
+  return (
+    <div className="space-y-4">
+      <Label className="text-sm font-medium">Observer Tab Visibility</Label>
+      <p className="text-xs text-muted-foreground">
+        Choose which analytics tabs are visible to observers
+      </p>
+      <SettingToggle
+        label="Scores Tab"
+        settingKey="analytics_observer_scores_tab"
+        value={settings.analytics_observer_scores_tab || 'true'}
+      />
+      <SettingToggle
+        label="Progress Tab"
+        settingKey="analytics_observer_progress_tab"
+        value={settings.analytics_observer_progress_tab || 'true'}
+      />
+      <SettingToggle
+        label="Juror Stats Tab"
+        settingKey="analytics_observer_juror_tab"
+        value={settings.analytics_observer_juror_tab || 'true'}
+      />
+      <SettingToggle
+        label="Comparison Tab"
+        settingKey="analytics_observer_comparison_tab"
+        value={settings.analytics_observer_comparison_tab || 'true'}
+      />
+      <div className="border-t pt-4 space-y-3">
+        <Label className="text-sm font-medium">PDF Reports</Label>
+        <SettingToggle
+          label="Enable PDF Report Generation"
+          description="Allow admins and observers to generate PDF reports"
+          settingKey="analytics_pdf_enabled"
+          value={settings.analytics_pdf_enabled || 'true'}
+        />
+      </div>
+    </div>
+  )
+}
+
+function AuditSettingsSection({ settings }: { settings: Record<string, string> }) {
+  return (
+    <div className="space-y-4">
+      <SettingInput
+        label="Retention Period (days)"
+        description="How long audit log entries are kept before automatic cleanup"
+        settingKey="audit_retention_days"
+        value={settings.audit_retention_days || '365'}
+        type="number"
+      />
+      <div className="border-t pt-4 space-y-3">
+        <SettingToggle
+          label="Enable Anomaly Detection"
+          description="Detect suspicious patterns like rapid actions or off-hours access"
+          settingKey="anomaly_detection_enabled"
+          value={settings.anomaly_detection_enabled || 'false'}
+        />
+        <SettingInput
+          label="Rapid Actions Threshold"
+          description="Maximum actions per minute before flagging as anomalous"
+          settingKey="anomaly_rapid_actions_threshold"
+          value={settings.anomaly_rapid_actions_threshold || '30'}
+          type="number"
+        />
+        <SettingInput
+          label="Off-Hours Start (UTC)"
+          description="Start hour for off-hours monitoring (0-23)"
+          settingKey="anomaly_off_hours_start"
+          value={settings.anomaly_off_hours_start || '22'}
+          type="number"
+        />
+        <SettingInput
+          label="Off-Hours End (UTC)"
+          description="End hour for off-hours monitoring (0-23)"
+          settingKey="anomaly_off_hours_end"
+          value={settings.anomaly_off_hours_end || '6'}
+          type="number"
+        />
+      </div>
+    </div>
+  )
+}
+
+function LocalizationSettingsSection({ settings }: { settings: Record<string, string> }) {
+  const mutation = useSettingsMutation()
+  const enabledLocales = (settings.localization_enabled_locales || 'en').split(',')
+
+  const toggleLocale = (locale: string) => {
+    const current = new Set(enabledLocales)
+    if (current.has(locale)) {
+      if (current.size <= 1) {
+        toast.error('At least one locale must be enabled')
+        return
+      }
+      current.delete(locale)
+    } else {
+      current.add(locale)
+    }
+    mutation.mutate({
+      key: 'localization_enabled_locales',
+      value: Array.from(current).join(','),
+    })
+  }
+
+  return (
+    <div className="space-y-4">
+      <div className="space-y-3">
+        <Label className="text-sm font-medium">Enabled Languages</Label>
+        <div className="space-y-2">
+          <div className="flex items-center justify-between rounded-lg border p-3">
+            <div className="flex items-center gap-2">
+              <span className="font-medium text-sm">EN</span>
+              <span className="text-sm text-muted-foreground">English</span>
+            </div>
+            <Checkbox
+              checked={enabledLocales.includes('en')}
+              onCheckedChange={() => toggleLocale('en')}
+              disabled={mutation.isPending}
+            />
+          </div>
+          <div className="flex items-center justify-between rounded-lg border p-3">
+            <div className="flex items-center gap-2">
+              <span className="font-medium text-sm">FR</span>
+              <span className="text-sm text-muted-foreground">Fran&ccedil;ais</span>
+            </div>
+            <Checkbox
+              checked={enabledLocales.includes('fr')}
+              onCheckedChange={() => toggleLocale('fr')}
+              disabled={mutation.isPending}
+            />
+          </div>
+        </div>
+      </div>
+      <SettingSelect
+        label="Default Locale"
+        description="The default language for new users"
+        settingKey="localization_default_locale"
+        value={settings.localization_default_locale || 'en'}
+        options={[
+          { value: 'en', label: 'English' },
+          { value: 'fr', label: 'Fran\u00e7ais' },
+        ]}
+      />
+    </div>
+  )
+}