chore(llm-pi-ai): bump pi-ai to 0.81.1 for the gpt-5.6 model catalog

pi-ai 0.80 restructured its entrypoints: the static catalog reads now
live on /providers/all as getBuiltinModels/getBuiltinProviders (keyed by
the catalog-only BuiltinProvider type, replacing KnownProvider at those
call sites), and the global streamSimple moved to /compat. The config
schema gains the new 'max' reasoning level.

packages/llm/llm-pi-ai/tests/adapter.spec.ts

@@ -5,8 +5,8 @@ import { Context } from 'cordis'
 import LlmService, { CONTEXT_WINDOW_EXCEEDED_CODE, LlmError, userAgent } from '@deepseek-ai/dsh-llm'
 import * as LlmPiAi from '@deepseek-ai/dsh-llm-pi-ai'
 import { PiAiAdapter } from '@deepseek-ai/dsh-llm-pi-ai'
-import { getModels } from '@earendil-works/pi-ai'
 import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
+import { getBuiltinModels } from '@earendil-works/pi-ai/providers/all'
 import { resolveProfiles } from '../src/config.ts'
 import { assemble } from './assemble.ts'
 
@@ -244,7 +244,7 @@ describe('PiAiAdapter provider routing', () => {
   })
 
   it('uses the resolved catalog context window for usage-based overflow detection', async () => {
-    const model = getModels('deepseek').find(candidate => candidate.id === 'deepseek-v4-flash')
+    const model = getBuiltinModels('deepseek').find(candidate => candidate.id === 'deepseek-v4-flash')
     if (model === undefined) throw new Error('deepseek-v4-flash missing from pi-ai test catalog')
     const events = [
       '{"choices":[{"delta":{"role":"assistant","content":""},"index":0,"finish_reason":null}]}',