feat(chat): complete runtime decoupling — compositions back to @cacheplane/chat (#136)

* docs: phase-2 design for finishing chat-runtime decoupling

Defines the ChatAgentWithHistory sub-contract, ChatCheckpoint neutral
shape, file-movement plan (three compositions back to @cacheplane/chat),
and public-API delta. Replay/fork stay as composition outputs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* docs: phase-2 implementation plan

9 tasks: add sub-contract types, extend mock/conformance, widen
toChatAgent, move three compositions back to @cacheplane/chat,
rebind cockpit consumers, verify dep graph.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* feat(chat): add ChatAgentWithHistory sub-contract and ChatCheckpoint

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* feat(chat): extend mockChatAgent with optional history

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* test(chat): add ChatAgentWithHistory conformance helper

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* feat(langgraph): widen toChatAgent to ChatAgentWithHistory, translate history

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* refactor(chat,langgraph): move chat-timeline primitive to chat, retarget to ChatAgentWithHistory

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* refactor(chat,langgraph): move chat-timeline-slider to chat, retarget to ChatAgentWithHistory

Moves ChatTimelineSliderComponent from @cacheplane/langgraph to @cacheplane/chat,
replacing the LangGraph-specific AgentRef/ThreadState types with the runtime-neutral
ChatAgentWithHistory/ChatCheckpoint contract. Updates both public-api.ts files accordingly.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* refactor(chat,langgraph): move chat-debug composition tree to chat, retarget to ChatCheckpoint

Moves all 11 files from libs/langgraph/src/lib/compositions/chat-debug/ to
libs/chat/src/lib/compositions/chat-debug/. Rewires chat-debug.component.ts
to use ChatAgentWithHistory (replacing AgentRef + toChatAgent adapter) and
debug-utils.ts to consume ChatCheckpoint (replacing ThreadState). Updates
public APIs: ChatDebugComponent exported from @cacheplane/chat; all debug-*
re-exports removed from @cacheplane/langgraph.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* refactor(cockpit): rebind chat-debug and chat-timeline demos to @cacheplane/chat

Move ChatDebugComponent and ChatTimelineSliderComponent imports from @cacheplane/langgraph to @cacheplane/chat, and update consumer bindings to use [agent] instead of [ref] for consistency with Phase-2 primitives.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore(chat): allow vitest in @nx/dependency-checks ignore list

Conformance helpers (chat-agent-conformance, chat-agent-with-history-
conformance) legitimately import from vitest. Adding to ignoredDependencies
matches how vite/@nx/vite are already excluded.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore(langgraph): drop unused @angular/common, @angular/platform-browser peer-deps

After the chat-debug tree moved to @cacheplane/chat in Phase-2,
@cacheplane/langgraph no longer consumes NgTemplateOutlet or
DomSanitizer. @nx/dependency-checks correctly flagged both as unused.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: blove

cockpit/chat/debug/angular/src/app/debug.component.ts

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0
 import { Component } from '@angular/core';
-import { ChatDebugComponent } from '@cacheplane/langgraph';
-import { agent } from '@cacheplane/langgraph';
+import { ChatDebugComponent } from '@cacheplane/chat';
+import { agent, toChatAgent } from '@cacheplane/langgraph';
 import { ExampleChatLayoutComponent } from '@cacheplane/example-layouts';
 import { environment } from '../environments/environment';
 
@@ -16,7 +16,7 @@ import { environment } from '../environments/environment';
   imports: [ChatDebugComponent, ExampleChatLayoutComponent],
   template: `
     <example-chat-layout>
-      <chat-debug main [ref]="stream" />
+      <chat-debug main [agent]="chatAgent" />
     </example-chat-layout>
   `,
 })
@@ -25,4 +25,5 @@ export class DebugPageComponent {
     apiUrl: environment.langGraphApiUrl,
     assistantId: environment.streamingAssistantId,
   });
+  protected readonly chatAgent = toChatAgent(this.stream);
 }

cockpit/chat/timeline/angular/src/app/timeline.component.ts

@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0
 import { Component } from '@angular/core';
-import { ChatComponent } from '@cacheplane/chat';
+import { ChatComponent, ChatTimelineSliderComponent } from '@cacheplane/chat';
 import { ExampleChatLayoutComponent } from '@cacheplane/example-layouts';
-import { agent, toChatAgent, ChatTimelineSliderComponent } from '@cacheplane/langgraph';
+import { agent, toChatAgent } from '@cacheplane/langgraph';
 import { environment } from '../environments/environment';
 
 /**
@@ -20,7 +20,7 @@ import { environment } from '../environments/environment';
       <div sidebar class="p-4 space-y-4" style="background: var(--chat-bg, #171717); color: var(--chat-text, #e0e0e0);">
         <h3 class="text-xs font-semibold uppercase tracking-wide"
             style="color: var(--chat-text-muted, #777);">Timeline</h3>
-        <chat-timeline-slider [ref]="stream" />
+        <chat-timeline-slider [agent]="chatAgent" />
         <div class="mt-4">
           <h4 class="text-xs font-semibold uppercase tracking-wide mb-2"
               style="color: var(--chat-text-muted, #777);">How It Works</h4>