feat(memory): implement stability stage

Co-authored-by: multica-agent <github@multica.ai>

apps/web/server/utils/ai-provider.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { buildJsonCompletion, parseJsonCompletion, resolveAiProvider } from './ai-provider'
+import { buildJsonCompletion, parseAiUsage, parseJsonCompletion, resolveAiProvider } from './ai-provider'
 
 const request = { system: 'Return JSON.', messages: [{ role: 'user' as const, content: 'Create a world' }], schemaName: 'world', jsonSchema: { type: 'object' } }
 
@@ -22,4 +22,11 @@ describe('AI provider adapter', () => {
     expect(() => parseJsonCompletion({ choices: [] })).toThrow()
     expect(parseJsonCompletion({ choices: [{ message: { content: '{"ok":true}' } }] })).toEqual({ ok: true })
   })
+
+  it('normalizes provider usage telemetry', () => {
+    expect(parseAiUsage({
+      choices: [{ message: { content: '{}' } }],
+      usage: { prompt_tokens: 120, completion_tokens: 30, cost: 0.0042 },
+    })).toEqual({ inputTokens: 120, outputTokens: 30, costUsd: 0.0042 })
+  })
 })