feat: Phase 5 & 6 — usability, compliance hardening, analytics

Phase 5 (usability + compliance):
- In-app notification bell/badge: migration 016 adds read state + per-user
  RLS + create_in_app_notification SECURITY DEFINER RPC; /api/notifications;
  wired into incident creation, CAPA assign/verify, escalation cron
- Incident closure: new POST /api/incidents/[id]/close (requires verification
  status + all CAPAs verified); migration 017 locks closed incidents at DB
  level (update/delete triggers) with append-only incident_addenda + UI panel
- Server-side pagination on HSE/supervisor incident inboxes (.range, 25/page)
- Investigation form: alcohol/urine test result + witness statement refs
  (existing schema columns, now editable)
- Type-specific intake fields: migration 018 adds incidents.type_details
  JSONB; whitelist validation; environmental/asset/security/fire field
  groups in report form; EN/MS/ZH labels; offline queue support
- JKKP 8 annual register CSV export (/api/reports/jkkp8) + dashboard button
  + January statutory deadline banner
- Admin page: user invite (service-role client), role/site/active management,
  site + zone CRUD with QR report links — replaces Phase 0 stub
- Evidence gallery thumbnails via Supabase render transform with fallback

Phase 6 (analytics):
- 12-month stacked trend chart (leading/lagging/other) + top root causes
  (lib/dashboard/trends.ts pure helpers)
- AI rising-risk zones: /api/dashboard/ai/risk-flags aggregates 90-day
  zone stats, claude-opus-4-8 forced tool_use, panel on HSE + management
  dashboards, suggestion audit-logged

Also fixes 9 pre-existing missing /ims basePath prefixes in client fetches
and download links.

132 tests passing, tsc clean, next build clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CPf5Rc8QPx6V8KLEEgfKEQ

app/api/admin/sites/route.ts

@@ -0,0 +1,57 @@
+export const dynamic = 'force-dynamic'
+
+import { NextRequest, NextResponse } from 'next/server'
+import { createClient } from '@/lib/supabase/server'
+
+async function requireAdmin() {
+  const supabase = await createClient()
+  const { data: { user }, error } = await supabase.auth.getUser()
+  if (error || !user) return { supabase, user: null }
+  const { data: profile } = await supabase
+    .from('users').select('role').eq('id', user.id).single()
+  if (!profile || profile.role !== 'admin') return { supabase, user: null }
+  return { supabase, user }
+}
+
+export async function POST(request: NextRequest) {
+  const { supabase, user } = await requireAdmin()
+  if (!user) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
+
+  const body: { kind?: 'site' | 'zone'; name?: string; address?: string; site_id?: string } =
+    await request.json().catch(() => ({}))
+  const name = (body.name ?? '').trim()
+  if (!name) return NextResponse.json({ error: 'name required' }, { status: 422 })
+
+  if (body.kind === 'zone') {
+    if (!body.site_id) return NextResponse.json({ error: 'site_id required for zone' }, { status: 422 })
+    const { data: zone, error } = await supabase
+      .from('zones')
+      .insert({ site_id: body.site_id, name })
+      .select('id, qr_code_token')
+      .single()
+    if (error || !zone) return NextResponse.json({ error: 'Insert failed' }, { status: 500 })
+
+    await supabase.rpc('write_audit_log', {
+      p_table_name: 'zones',
+      p_record_id: zone.id,
+      p_action: 'INSERT',
+      p_new_value: { name, site_id: body.site_id },
+    })
+    return NextResponse.json({ id: zone.id, qr_code_token: zone.qr_code_token }, { status: 201 })
+  }
+
+  const { data: site, error } = await supabase
+    .from('sites')
+    .insert({ name, address: body.address ?? null })
+    .select('id')
+    .single()
+  if (error || !site) return NextResponse.json({ error: 'Insert failed' }, { status: 500 })
+
+  await supabase.rpc('write_audit_log', {
+    p_table_name: 'sites',
+    p_record_id: site.id,
+    p_action: 'INSERT',
+    p_new_value: { name, address: body.address ?? null },
+  })
+  return NextResponse.json({ id: site.id }, { status: 201 })
+}