fix: RLS guard in match_incidents + try/catch around AI/embed calls

- Add new migration 20260711000013_match_incidents_auth_guard.sql that
  replaces match_incidents with an inline auth guard: callers without
  hse/admin role receive PGRST301 Forbidden, closing the SECURITY
  DEFINER RLS bypass.
- Wrap anthropic.messages.create() in try/catch returning 503 in all
  four AI routes: quality-check, triage-suggest, rca-draft, similar.
- Wrap JSON.parse(inc.embedding) and embedText() in similar/route.ts
  in a shared try/catch returning 503 Embedding service unavailable.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FFDuBhMKvoWjrWT3ZnGmmr

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

@@ -41,7 +41,9 @@ export async function POST(
   const siteName = (incident.sites as unknown as { name: string } | null)?.name ?? 'Unknown'
   const zoneName = (incident.zones as unknown as { name: string } | null)?.name ?? 'Unknown'
 
-  const message = await anthropic.messages.create({
+  let message: Awaited<ReturnType<typeof anthropic.messages.create>>
+  try {
+    message = await anthropic.messages.create({
       model: 'claude-opus-4-8',
       thinking: { type: 'adaptive' },
       max_tokens: 2048,
@@ -94,6 +96,9 @@ Triage notes: ${inc.triage_notes ?? '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.`,
       }],
     })
+  } catch {
+    return NextResponse.json({ error: 'AI service unavailable' }, { status: 503 })
+  }
 
   const toolBlock = message.content.find(b => b.type === 'tool_use')
   if (!toolBlock || toolBlock.type !== 'tool_use')

app/api/incidents/[id]/ai/triage-suggest/route.ts

@@ -32,7 +32,9 @@ export async function POST(
     medical_status: string | null
   }
 
-  const message = await anthropic.messages.create({
+  let message: Awaited<ReturnType<typeof anthropic.messages.create>>
+  try {
+    message = await anthropic.messages.create({
       model: 'claude-opus-4-8',
       thinking: { type: 'adaptive' },
       max_tokens: 1024,
@@ -69,6 +71,9 @@ Asset/equipment involved: ${inc.asset_involved ? 'yes' : 'no'}
 Suggest severity (1–5) and tick the appropriate NADOPOD 2004 flags. Give a one-sentence rationale.`,
       }],
     })
+  } catch {
+    return NextResponse.json({ error: 'AI service unavailable' }, { status: 503 })
+  }
 
   const toolBlock = message.content.find(b => b.type === 'tool_use')
   if (!toolBlock || toolBlock.type !== 'tool_use')

app/api/incidents/[id]/similar/route.ts

@@ -27,6 +27,7 @@ export async function GET(
   const inc = incident as { id: string; description: string; embedding: string | null }
 
   let embeddingVec: number[]
+  try {
     if (inc.embedding) {
       embeddingVec = JSON.parse(inc.embedding) as number[]
     } else {
@@ -35,6 +36,9 @@ export async function GET(
         embedding: `[${embeddingVec.join(',')}]` as unknown as string,
       }).eq('id', id)
     }
+  } catch {
+    return NextResponse.json({ error: 'Embedding service unavailable' }, { status: 503 })
+  }
 
   const { data: similar } = await supabase.rpc('match_incidents', {
     query_embedding: `[${embeddingVec.join(',')}]`,

app/api/incidents/ai/quality-check/route.ts

@@ -19,7 +19,9 @@ export async function POST(request: NextRequest) {
     return NextResponse.json({ error: 'description and incident_type required' }, { status: 422 })
   }
 
-  const message = await anthropic.messages.create({
+  let message: Awaited<ReturnType<typeof anthropic.messages.create>>
+  try {
+    message = await anthropic.messages.create({
       model: 'claude-opus-4-8',
       thinking: { type: 'adaptive' },
       max_tokens: 1024,
@@ -52,6 +54,9 @@ Description: ${body.description}
 Score 1–10 based on: specificity (location, time, persons involved), completeness (what happened + immediate actions), and clarity. Score 6 or above passes. If score is below 6, give up to 3 actionable suggestions.`,
       }],
     })
+  } catch {
+    return NextResponse.json({ error: 'AI service unavailable' }, { status: 503 })
+  }
 
   const toolBlock = message.content.find(b => b.type === 'tool_use')
   if (!toolBlock || toolBlock.type !== 'tool_use') {

supabase/migrations/20260711000013_match_incidents_auth_guard.sql

@@ -0,0 +1,43 @@
+-- Add authorization guard to match_incidents to enforce DB-level access control.
+-- Without this, SECURITY DEFINER bypasses RLS for any direct caller.
+create or replace function match_incidents(
+  query_embedding vector(1024),
+  exclude_id      uuid,
+  match_count     int default 5
+)
+returns table (
+  id            uuid,
+  reference_no  text,
+  incident_type text,
+  description   text,
+  severity      int,
+  similarity    float
+)
+language plpgsql
+security definer
+as $$
+begin
+  -- Enforce that only hse/admin roles can call this function directly
+  if not exists (
+    select 1 from public.users
+    where id = auth.uid()
+    and role in ('hse', 'admin')
+  ) then
+    raise exception 'Forbidden' using errcode = 'PGRST301';
+  end if;
+
+  return query
+  select
+    i.id,
+    i.reference_no,
+    i.incident_type,
+    i.description,
+    i.severity,
+    1 - (i.embedding <=> query_embedding) as similarity
+  from incidents i
+  where i.id != exclude_id
+    and i.embedding is not null
+  order by i.embedding <=> query_embedding
+  limit match_count;
+end;
+$$;