fix: rename deepseek model from deepseek-chat to deepseek-v4-pro

DeepSeek API deprecated deepseek-chat model. Returns error:
'the supported API model names are deepseek-v4-pro or deepseek-v4-flash'

Affected all 4 AI endpoints:
- risk-flags (90-day dashboard)
- triage-suggest
- rca-draft
- quality-check

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

app/api/dashboard/ai/risk-flags/route.ts

@@ -109,7 +109,7 @@ export async function POST() {
   let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
     res = await client.chat.completions.create({
-      model: 'deepseek-chat',
+      model: 'deepseek-v4-pro',
       max_tokens: 2048,
       tools: [{
         type: 'function',
@@ -178,7 +178,7 @@ ${JSON.stringify(aggregates, null, 2)}
 
   await withUser(session.sub, async tx =>
     writeAuditLog(tx, 'incidents', session.sub, 'ai_risk_flags',
-      { flags, summary: input.summary, model: 'deepseek-chat' })
+      { flags, summary: input.summary, model: 'deepseek-v4-pro' })
   )
 
   return NextResponse.json({ flags, summary: input.summary })

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

@@ -59,7 +59,7 @@ export async function POST(
   let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
     res = await client.chat.completions.create({
-      model: 'deepseek-chat',
+      model: 'deepseek-v4-pro',
       max_tokens: 2048,
       tools: [{
         type: 'function',
@@ -135,7 +135,7 @@ Provide 3–5 Why steps drilling from immediate cause to root cause. Give a one-
   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',
+      model: 'deepseek-v4-pro',
     })
   })
 

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

@@ -50,7 +50,7 @@ export async function POST(
   let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
     res = await client.chat.completions.create({
-      model: 'deepseek-chat',
+      model: 'deepseek-v4-pro',
       max_tokens: 1024,
       tools: [{
         type: 'function',
@@ -118,7 +118,7 @@ Suggest severity (1–5) and tick the appropriate NADOPOD 2004 flags. Give a one
   }
 
   await withUser(session.sub, async tx => {
-    await writeAuditLog(tx, 'incidents', id, 'ai_triage_suggest', { suggestion: input, model: 'deepseek-chat' })
+    await writeAuditLog(tx, 'incidents', id, 'ai_triage_suggest', { suggestion: input, model: 'deepseek-v4-pro' })
   })
 
   return NextResponse.json(input)

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

@@ -42,7 +42,7 @@ export async function POST(request: NextRequest) {
   let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
     res = await client.chat.completions.create({
-      model: 'deepseek-chat',
+      model: 'deepseek-v4-pro',
       max_tokens: 1024,
       tools: [{
         type: 'function',
@@ -99,7 +99,7 @@ Score 1–10 based on: specificity (location, time, persons involved), completen
   // audit write uses session.sub as a pseudo record-id (no incident_id at this stage)
   await withUser(session.sub, async tx => {
     await writeAuditLog(tx, 'incidents', session.sub, 'ai_quality_check', {
-      score: input.score, passes: input.passes, model: 'deepseek-chat',
+      score: input.score, passes: input.passes, model: 'deepseek-v4-pro',
     })
   })