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/incidents/[id]/close/route.ts

@@ -0,0 +1,65 @@
+export const dynamic = 'force-dynamic'
+
+import { NextRequest, NextResponse } from 'next/server'
+import { createClient } from '@/lib/supabase/server'
+import { createInAppNotifications } from '@/lib/notifications/in-app'
+
+export async function POST(
+  _request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const { id } = await params
+  const supabase = await createClient()
+
+  const { data: { user }, error: authError } = await supabase.auth.getUser()
+  if (authError || !user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const { data: profile } = await supabase
+    .from('users').select('role').eq('id', user.id).single()
+  if (!profile || !['hse', 'admin'].includes(profile.role))
+    return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
+
+  const { data: incident } = await supabase
+    .from('incidents')
+    .select('status, reference_no, reported_by')
+    .eq('id', id)
+    .single()
+  if (!incident) return NextResponse.json({ error: 'Not found' }, { status: 404 })
+  if (incident.status === 'closed')
+    return NextResponse.json({ error: 'Already closed' }, { status: 409 })
+  if (incident.status !== 'verification')
+    return NextResponse.json({ error: 'Incident must be in verification status' }, { status: 409 })
+
+  const { data: openCapas } = await supabase
+    .from('capa_actions')
+    .select('id')
+    .eq('incident_id', id)
+    .not('status', 'in', '(verified,closed)')
+  if (openCapas && openCapas.length > 0)
+    return NextResponse.json({ error: 'All CAPA actions must be verified before closure' }, { status: 409 })
+
+  const closedAt = new Date().toISOString()
+  const { error } = await supabase
+    .from('incidents')
+    .update({ status: 'closed', closed_at: closedAt })
+    .eq('id', id)
+  if (error) return NextResponse.json({ error: 'Update failed' }, { status: 500 })
+
+  await supabase.rpc('write_audit_log', {
+    p_table_name: 'incidents',
+    p_record_id: id,
+    p_action: 'closed',
+    p_new_value: { status: 'closed', closed_at: closedAt, closed_by: user.id },
+  })
+
+  if (incident.reported_by) {
+    await createInAppNotifications(supabase, [{
+      userId: incident.reported_by,
+      title: `Your incident report ${incident.reference_no ?? ''} has been closed`,
+      link: '/reporter',
+      incidentId: id,
+    }])
+  }
+
+  return NextResponse.json({ ok: true, closed_at: closedAt })
+}