Merge refreshed schema DSL into canonical tool output

# Conflicts:
#	docs/config-catalog.md
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.1.jsonl
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.2.jsonl
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.jsonl
#	packages/context/workspace-context/tests/workspace-context.spec.ts
#	packages/core/tools/tests/tools.spec.ts
#	packages/ui/tui/src/index.ts
#	packages/ui/tui/tests/tui.snapshot.ts

packages/llm/llm-deepseek/src/serialize.ts

@@ -40,10 +40,15 @@ function serializeAssistant(message: Message): WireMessage {
 
   return {
     role: 'assistant',
-    // Tool-call turns send "" rather than null: the live API answers both,
-    // but the official samples replay message.content verbatim (which is ""
-    // for pure tool-call responses) and some gateways reject null outright.
-    content: text.length > 0 ? text : toolCalls.length > 0 ? '' : null,
+    // Text-less turns send "" — NEVER null. Pure tool-call turns: the
+    // official samples replay message.content verbatim (which is "") and
+    // some gateways reject null outright. Reasoning-ONLY turns (the model
+    // can answer entirely in the reasoning channel, e.g. a v4-flash
+    // greeting): the live API rejects null-content/no-tool_calls assistant
+    // messages with a 400 ("content or tool_calls must be set"), and since
+    // the message sits durably in the session log, a null here bricks every
+    // later turn of that session.
+    content: text,
     // Official passback rule (guides/thinking_mode.mdx): reasoning_content
     // must return on tool-call turns; it is ignored on plain turns, so we
     // drop it there to save tokens.

packages/llm/llm-deepseek/tests/serialize.spec.ts

@@ -187,12 +187,22 @@ describe('serializeRequest', () => {
   })
 })
 
-describe('assistant empty and tool-call content shapes', () => {
-  it('serializes a content-less, tool-call-less assistant message as null content', () => {
-    // Aborted/empty assistant turns: no text, no calls → null (the wire
-    // accepts it; "" is reserved for tool-call turns per the samples).
+describe('review fixes: assistant content shapes', () => {
+  it('serializes a content-less, tool-call-less assistant message as "" content, never null', () => {
+    // Aborted/empty assistant turns: no text, no calls → "". The earlier
+    // null shape was live-falsified: the API 400s a null-content assistant
+    // message without tool_calls ("content or tool_calls must be set").
     const wire = serializeMessages([{ role: 'assistant', content: [] }])
-    expect(wire).toEqual([{ role: 'assistant', content: null }])
+    expect(wire).toEqual([{ role: 'assistant', content: '' }])
+  })
+
+  it('serializes a reasoning-ONLY assistant message as "" content with the reasoning dropped', () => {
+    // The model can answer entirely in the reasoning channel (a v4-flash
+    // greeting did, live). The passback rule keeps reasoning_content off
+    // plain turns, and content must still be SET — a null here poisoned the
+    // session log and bricked every later turn of that session.
+    const wire = serializeMessages([{ role: 'assistant', content: [{ type: 'reasoning', text: '你好！有什么我可以帮你的吗？' }] }])
+    expect(wire).toEqual([{ role: 'assistant', content: '' }])
   })
 
   it('serializes tool-call turns with empty string content, not null', () => {

packages/llm/llm-pi-ai/package.json

@@ -33,7 +33,7 @@
     "cordis": "^4.0.0-rc.7"
   },
   "dependencies": {
-    "@earendil-works/pi-ai": "^0.79.1",
+    "@earendil-works/pi-ai": "^0.81.1",
     "schemastery": "^3.18.0"
   },
   "devDependencies": {

packages/llm/llm-pi-ai/src/adapter.ts

@@ -4,13 +4,11 @@
  * @module dsh-llm-pi-ai/adapter
  */
 
-import {
-  getModels,
-  streamSimple,
-} from '@earendil-works/pi-ai'
+import { streamSimple } from '@earendil-works/pi-ai/compat'
+import { getBuiltinModels } from '@earendil-works/pi-ai/providers/all'
+import type { BuiltinProvider } from '@earendil-works/pi-ai/providers/all'
 import type {
   Api,
-  KnownProvider,
   Model,
   SimpleStreamOptions,
 } from '@earendil-works/pi-ai'
@@ -33,7 +31,7 @@ export interface PiAiAdapterOptions {
  * override, preserving the catalog's API/capability/compatibility metadata.
  */
 function resolveModel(profile: PiAiProviderProfile, modelId: string): Model<Api> {
-  const model = getModels(profile.provider as KnownProvider).find(candidate => candidate.id === modelId) as Model<Api> | undefined
+  const model = getBuiltinModels(profile.provider as BuiltinProvider).find(candidate => candidate.id === modelId) as Model<Api> | undefined
   if (model === undefined) {
     throw new LlmError(`pi-ai provider "${profile.provider}" has no catalog model "${modelId}"`, 'UNKNOWN_MODEL')
   }
@@ -82,7 +80,7 @@ export class PiAiAdapter extends LlmAdapter {
     if (profile === undefined) {
       return Promise.reject(new LlmError(`pi-ai adapter does not own provider "${provider}"`, 'NO_ADAPTER'))
     }
-    return Promise.resolve(getModels(profile.provider as KnownProvider).map(model => ({
+    return Promise.resolve(getBuiltinModels(profile.provider as BuiltinProvider).map(model => ({
       provider,
       id: model.id,
       name: model.name,

packages/llm/llm-pi-ai/src/config.ts

@@ -4,7 +4,7 @@
  * @module dsh-llm-pi-ai/config
  */
 
-import { getProviders } from '@earendil-works/pi-ai'
+import { getBuiltinProviders } from '@earendil-works/pi-ai/providers/all'
 import type { CacheRetention, ThinkingBudgets, ThinkingLevel, Transport } from '@earendil-works/pi-ai'
 import z from 'schemastery'
 import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
@@ -62,7 +62,7 @@ const profile = z.object({
   apiKey: z.string(),
   baseURL: z.string(),
   headers: z.dict(z.string()),
-  reasoning: z.union(['minimal', 'low', 'medium', 'high', 'xhigh']),
+  reasoning: z.union(['minimal', 'low', 'medium', 'high', 'xhigh', 'max']),
   thinkingBudgets,
   cacheRetention: z.union(['none', 'short', 'long']),
   transport: z.union(['sse', 'websocket', 'websocket-cached', 'auto']),
@@ -84,7 +84,7 @@ export const Config: z<Config> = z.object({
  */
 export function resolveProfiles(profiles: readonly PiAiProviderProfile[]): ResolvedPiAiProviderProfile[] {
   if (profiles.length === 0) throw new Error('llm-pi-ai: providers must contain at least one profile')
-  const supported = new Set<string>(getProviders())
+  const supported = new Set<string>(getBuiltinProviders())
   const seen = new Set<string>()
   return profiles.map((source) => {
     const legacy = source as PiAiProviderProfile & {

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}]}',

packages/llm/llm-pi-ai/tests/sdk-options.spec.ts

@@ -2,8 +2,10 @@ import { afterEach, describe, expect, it, vi } from 'vitest'
 
 const streamSimple = vi.hoisted(() => vi.fn())
 
-vi.mock('@earendil-works/pi-ai', async (importOriginal) => {
-  const actual = await importOriginal<typeof import('@earendil-works/pi-ai')>()
+// The 0.81 SDK moved `streamSimple` to the compat entry; the adapter imports it
+// from there, so the mock must target the same specifier.
+vi.mock('@earendil-works/pi-ai/compat', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@earendil-works/pi-ai/compat')>()
   return { ...actual, streamSimple }
 })