feat: switch AI provider from Anthropic to DeepSeek

- lib/claude/client.ts: replace Anthropic SDK with openai package pointed at DeepSeek baseURL
- 4 AI routes: port tool definitions, tool_choice, and output parsing to OpenAI function-calling format
- Drop thinking:{type:'adaptive'} (no DeepSeek equivalent); model string → deepseek-chat
- settings/route.ts: add DEEPSEEK_API_KEY to ALLOWED_KEYS
- migration: seed DEEPSEEK_API_KEY placeholder row in app_settings
- tests: update 3 AI route tests to mock createDeepSeekClient + OpenAI response shape

Voyage AI embedding path untouched (DeepSeek has no embeddings endpoint).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CPf5Rc8QPx6V8KLEEgfKEQ

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

@@ -2,7 +2,7 @@ export const dynamic = 'force-dynamic'
 
 import { NextResponse } from 'next/server'
 import { createClient } from '@/lib/supabase/server'
-import { createAnthropicClient } from '@/lib/claude/client'
+import { createDeepSeekClient } from '@/lib/claude/client'
 import { getApiKey } from '@/lib/settings'
 
 type ZoneAggregate = {
@@ -92,41 +92,43 @@ export async function POST() {
     return NextResponse.json({ error: 'Rate limit: wait 60 seconds between AI requests' }, { status: 429 })
   }
 
-  const anthropicKey = await getApiKey(supabase, 'ANTHROPIC_API_KEY')
-  const anthropic = createAnthropicClient(anthropicKey)
+  const deepseekKey = await getApiKey(supabase, 'DEEPSEEK_API_KEY')
+  const client = createDeepSeekClient(deepseekKey)
 
-  let message: Awaited<ReturnType<typeof anthropic.messages.create>>
+  let res: Awaited<ReturnType<typeof client.chat.completions.create>>
   try {
-    message = await anthropic.messages.create({
-      model: 'claude-opus-4-8',
-      thinking: { type: 'adaptive' },
+    res = await client.chat.completions.create({
+      model: 'deepseek-chat',
       max_tokens: 2048,
       tools: [{
-        name: 'flag_rising_risk',
-        description: 'Flag warehouse zones showing rising safety risk from 90-day incident aggregates',
-        input_schema: {
-          type: 'object' as const,
-          properties: {
-            flags: {
-              type: 'array',
-              items: {
-                type: 'object',
-                properties: {
-                  zone: { type: 'string' },
-                  site: { type: 'string' },
-                  risk_level: { type: 'string', enum: ['low', 'medium', 'high'] },
-                  rationale: { type: 'string', description: 'One or two sentences citing the numbers' },
-                  recommended_action: { type: 'string', description: 'One concrete preventive action' },
+        type: 'function',
+        function: {
+          name: 'flag_rising_risk',
+          description: 'Flag warehouse zones showing rising safety risk from 90-day incident aggregates',
+          parameters: {
+            type: 'object',
+            properties: {
+              flags: {
+                type: 'array',
+                items: {
+                  type: 'object',
+                  properties: {
+                    zone: { type: 'string' },
+                    site: { type: 'string' },
+                    risk_level: { type: 'string', enum: ['low', 'medium', 'high'] },
+                    rationale: { type: 'string', description: 'One or two sentences citing the numbers' },
+                    recommended_action: { type: 'string', description: 'One concrete preventive action' },
+                  },
+                  required: ['zone', 'site', 'risk_level', 'rationale', 'recommended_action'],
                 },
-                required: ['zone', 'site', 'risk_level', 'rationale', 'recommended_action'],
               },
+              summary: { type: 'string', description: 'Two-sentence overall risk picture' },
             },
-            summary: { type: 'string', description: 'Two-sentence overall risk picture' },
+            required: ['flags', 'summary'],
           },
-          required: ['flags', 'summary'],
         },
       }],
-      tool_choice: { type: 'tool', name: 'flag_rising_risk' },
+      tool_choice: { type: 'function', function: { name: 'flag_rising_risk' } },
       messages: [{
         role: 'user',
         content: `You are an HSE risk analyst for a Malaysian 3PL warehouse operator. Below are 90-day incident aggregates per zone. "first_half" is incidents in days 90-46, "second_half" is days 45-0 — a rising second_half means worsening trend. Near-miss and hazard reports are leading indicators; injuries are lagging.
@@ -142,11 +144,13 @@ ${JSON.stringify(aggregates, null, 2)}
     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')
-    return NextResponse.json({ error: 'AI suggestion failed' }, { status: 500 })
+  const call = res.choices[0]?.message?.tool_calls?.[0]
+  if (!call || call.type !== 'function') return NextResponse.json({ error: 'AI suggestion failed' }, { status: 500 })
+
+  let input: { flags?: unknown; summary?: unknown }
+  try { input = JSON.parse(call.function.arguments) }
+  catch { return NextResponse.json({ error: 'AI returned unexpected structure' }, { status: 500 }) }
 
-  const input = toolBlock.input as { flags?: unknown; summary?: unknown }
   if (!Array.isArray(input.flags) || typeof input.summary !== 'string')
     return NextResponse.json({ error: 'AI returned unexpected structure' }, { status: 500 })
 
@@ -164,7 +168,7 @@ ${JSON.stringify(aggregates, null, 2)}
     p_table_name: 'incidents',
     p_record_id: user.id,
     p_action: 'ai_risk_flags',
-    p_new_value: { flags, summary: input.summary, model: 'claude-opus-4-8' } as never,
+    p_new_value: { flags, summary: input.summary, model: 'deepseek-chat' } as never,
   })
 
   return NextResponse.json({ flags, summary: input.summary })