feat(db): phase 4 group 3 — incident routes to Drizzle

Convert all 11 incident API routes from Supabase PostgREST to Drizzle
ORM with withUser/asAdmin/writeAuditLog patterns and RLS enforcement.
Only uploadEvidenceFile retains supabase client (Phase 5 storage work).

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

app/api/incidents/[id]/ai/rca-draft/route.ts

@@ -1,8 +1,11 @@
 export const dynamic = 'force-dynamic'
 
 import { NextRequest, NextResponse } from 'next/server'
-import { createClient } from '@/lib/supabase/server'
 import { getSession } from '@/lib/auth/get-session'
+import { withUser, asAdmin } from '@/lib/db/with-user'
+import { writeAuditLog } from '@/lib/db/audit'
+import { incidents, auditLog, sites, zones } from '@/lib/db/schema'
+import { eq, and, gte, sql } from 'drizzle-orm'
 import { createDeepSeekClient } from '@/lib/claude/client'
 import { getApiKey } from '@/lib/settings'
 
@@ -16,45 +19,43 @@ export async function POST(
   if (!['hse', 'admin'].includes(session.role))
     return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
 
-  const supabase = await createClient()
-
-  const since = new Date(Date.now() - 60_000).toISOString()
-  const { count: recentCount } = await supabase
-    .from('audit_log')
-    .select('id', { count: 'exact', head: true })
-    .eq('changed_by', session.sub)
-    .eq('action', 'ai_rca_draft')
-    .gte('changed_at', since)
-  if ((recentCount ?? 0) > 0)
+  // Rate limit
+  const since = new Date(Date.now() - 60_000)
+  const [rateRow] = await asAdmin(db =>
+    db.select({ cnt: sql<number>`count(*)` }).from(auditLog)
+      .where(and(
+        eq(auditLog.changedBy, session.sub),
+        eq(auditLog.action, 'ai_rca_draft'),
+        gte(auditLog.changedAt, since),
+      ))
+  )
+  if (Number(rateRow?.cnt ?? 0) > 0)
     return NextResponse.json({ error: 'Rate limited — please wait 60 seconds' }, { status: 429 })
 
   const deepseekKey = await getApiKey('DEEPSEEK_API_KEY')
   const client = createDeepSeekClient(deepseekKey)
 
-  const { data: incident } = await supabase
-    .from('incidents')
-    .select(`
-      id, incident_type, description, severity, injury_involved, medical_status,
-      is_fatality, is_serious_bodily_injury, triage_notes,
-      sites (name), zones (name)
-    `)
-    .eq('id', id)
-    .single()
+  const [incident] = await withUser(session.sub, async tx =>
+    tx.select({
+      incidentType: incidents.incidentType,
+      description: incidents.description,
+      severity: incidents.severity,
+      injuryInvolved: incidents.injuryInvolved,
+      medicalStatus: incidents.medicalStatus,
+      isFatality: incidents.isFatality,
+      isSeriousBodilyInjury: incidents.isSeriousBodilyInjury,
+      triageNotes: incidents.triageNotes,
+      siteName: sites.name,
+      zoneName: zones.name,
+    })
+    .from(incidents)
+    .leftJoin(sites, eq(incidents.siteId, sites.id))
+    .leftJoin(zones, eq(incidents.zoneId, zones.id))
+    .where(eq(incidents.id, id))
+    .limit(1)
+  )
   if (!incident) return NextResponse.json({ error: 'Not found' }, { status: 404 })
 
-  const inc = incident as {
-    incident_type: string
-    description: string
-    severity: number | null
-    injury_involved: boolean
-    medical_status: string | null
-    is_fatality: boolean
-    is_serious_bodily_injury: boolean
-    triage_notes: string | null
-  }
-  const siteName = (incident.sites as unknown as { name: string } | null)?.name ?? 'Unknown'
-  const zoneName = (incident.zones as unknown as { name: string } | null)?.name ?? 'Unknown'
-
   let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
     res = await client.chat.completions.create({
@@ -99,15 +100,15 @@ export async function POST(
         role: 'user',
         content: `You are an experienced HSE investigator for a Malaysian 3PL warehouse. Draft a 5-Why root cause analysis for this incident.
 
-Site: ${siteName}
-Zone: ${zoneName}
-Incident type: ${inc.incident_type}
-Description: ${inc.description}
-Severity: ${inc.severity ?? 'not yet assigned'}/5
-Injury involved: ${inc.injury_involved ? `yes — ${inc.medical_status}` : 'no'}
-Fatality: ${inc.is_fatality ? 'yes' : 'no'}
-Serious bodily injury: ${inc.is_serious_bodily_injury ? 'yes' : 'no'}
-Triage notes: ${inc.triage_notes ?? 'none'}
+Site: ${incident.siteName ?? 'Unknown'}
+Zone: ${incident.zoneName ?? 'Unknown'}
+Incident type: ${incident.incidentType}
+Description: ${incident.description}
+Severity: ${incident.severity ?? 'not yet assigned'}/5
+Injury involved: ${incident.injuryInvolved ? `yes — ${incident.medicalStatus}` : 'no'}
+Fatality: ${incident.isFatality ? 'yes' : 'no'}
+Serious bodily injury: ${incident.isSeriousBodilyInjury ? 'yes' : 'no'}
+Triage notes: ${incident.triageNotes ?? 'none'}
 
 Provide 3–5 Why steps drilling from immediate cause to root cause. Give a one-sentence root cause statement. Suggest 3 corrective/preventive actions appropriate for a Malaysian warehouse context.`,
       }],
@@ -131,14 +132,11 @@ Provide 3–5 Why steps drilling from immediate cause to root cause. Give a one-
     return NextResponse.json({ error: 'AI returned unexpected structure' }, { status: 500 })
   }
 
-  await supabase.rpc('write_audit_log', {
-    p_table_name: 'incidents',
-    p_record_id: id,
-    p_action: 'ai_rca_draft',
-    p_new_value: {
-      root_cause_summary: draft.root_cause_summary,
+  await withUser(session.sub, async tx => {
+    await writeAuditLog(tx, 'incidents', id, 'ai_rca_draft', {
+      root_cause_summary: draft.root_cause_summary as string,
       model: 'deepseek-chat',
-    } as never,
+    })
   })
 
   return NextResponse.json(draft)