feat: slot system + entries/priority/errorreport + typert generator

packages/client/ui-conversation/src/client/contract/views.ts

@@ -14,14 +14,14 @@ export interface ViewTab { id: string; label: string }
 
 /**
  * Per-session state shared by conversation, chat-view, and details slots.
- * Unknown persisted view ids fall back to the first registered view.
+ * Unknown persisted view ids fall back to the stable Chat view.
  */
 export interface ChatStoreState {
   /** Details-linkage channel (conversation writes, details reads). */
   selection: SelectionTarget | null
   /** Composer draft (persisted; survives session switches and reloads). */
   draft: string
-  /** Active conversation view id ('conversation.view' entry id); null falls back to the first view. */
+  /** Active conversation view id ('conversation.view' entry id); null falls back to Chat. */
   view: string | null
   /**
    * One-shot inspect handoff: chat writes the call to reveal, the trajectory

packages/client/ui-conversation/src/client/skeleton/ConversationRoot.module.css

@@ -280,7 +280,7 @@
   overflow-y: auto;
 }
 
-.scrollBody:has([data-conversation-composer-overlay]) > .viewArea {
+.scrollBody:has([data-conversation-composer-overlay]) > :global([data-slot='conversation.session']) > .viewArea {
   flex: 1 1 0;
   min-height: 0;
   overflow: hidden;

packages/client/ui-conversation/src/client/skeleton/ConversationSession.tsx

@@ -6,6 +6,7 @@ import type { SessionId, SessionListState, SessionSummary } from '@deepseek-ai/d
 import type {
   ConversationSessionHeaderSlotProps, ConversationSessionSlotProps,
 } from '../contract/slots.ts'
+import type { ViewTab } from '../contract/views.ts'
 import css from './ConversationRoot.module.css'
 
 /** Full props composed from the strict session body contract. */
@@ -19,6 +20,15 @@ interface Breadcrumb {
   readonly displayTitle: string
 }
 
+const DEFAULT_VIEW_ID = 'chat'
+
+/** Resolve by id and keep stale persisted selections on the stable Chat fallback. */
+function resolveActiveView(tabs: readonly ViewTab[], selectedId: string | null): ViewTab | undefined {
+  const requestedId = selectedId ?? DEFAULT_VIEW_ID
+  return tabs.find(view => view.id === requestedId)
+    ?? tabs.find(view => view.id === DEFAULT_VIEW_ID)
+}
+
 function deriveAncestry(list: SessionListState, id: SessionId): readonly Breadcrumb[] {
   const chain: Breadcrumb[] = []
   const seen = new Set<SessionId>()
@@ -54,8 +64,8 @@ export function ConversationSessionHeader({
 }: ConversationSessionHeaderProps) {
   useSyncExternalStore(views.subscribe, views.version)
   const tabs = views.list()
-  const activeId = useStore(s => s.view) ?? 'chat'
-  const active = tabs.find(view => view.id === activeId) ?? tabs[0]
+  const selectedId = useStore(s => s.view)
+  const active = resolveActiveView(tabs, selectedId)
   const ancestry = useSessions(s => deriveAncestry(s, sessionId), equalBreadcrumbs)
   const composerPhase = useSession(s => s.composerPhase)
   const blank = useSession(s => s.blank)
@@ -131,8 +141,8 @@ export function ConversationSession({
 }: ConversationSessionProps) {
   useSyncExternalStore(views.subscribe, views.version)
   const tabs = views.list()
-  const activeId = useStore(s => s.view) ?? 'chat'
-  const active = tabs.find(view => view.id === activeId) ?? tabs[0]
+  const selectedId = useStore(s => s.view)
+  const active = resolveActiveView(tabs, selectedId)
   const composerPhase = useSession(s => s.composerPhase)
   const blank = useSession(s => s.blank)
   const inputState = useInput(s => s)

packages/client/ui-conversation/tests/skeleton.client.spec.tsx

@@ -27,6 +27,7 @@ import type { InputBarProps } from '../src/client/skeleton/InputBar.tsx'
 import type {
   ComposerBarOwnerProps,
 } from '../src/client/contract/slots.ts'
+import type { ViewTab } from '../src/client/contract/views.ts'
 
 /** Machine-backed wiring over a sink spy. */
 function fakeWiring() {
@@ -96,6 +97,8 @@ function mount(
     summaryOrigin?: 'subagent'
     /** A composer block another plugin raised for this session. */
     composerBlock?: { reason: string }
+    /** Mutable view ledger used by registration-order regressions. */
+    viewTabs?: ViewTab[]
   } = {},
 ) {
   const root = sid('root')
@@ -123,6 +126,15 @@ function mount(
   const stop = vi.fn()
   const open = vi.fn()
   const slotCalls: string[] = []
+  const viewTabs = options.viewTabs ?? [
+    { id: 'chat', label: 'Chat' },
+    { id: 'trajectory', label: 'Trajectory' },
+  ]
+  const views = {
+    list: () => viewTabs,
+    subscribe: () => () => {},
+    version: () => 1,
+  }
   /** Owner share handed to the two composer tool-row seats, per render. */
   const seatOwners: { key: string; owner: unknown }[] = []
   let pickerOwner: unknown
@@ -146,14 +158,7 @@ function mount(
           useStore={bindSnapshotSelector(chat)}
           actions={chat.actions}
           renderSlot={renderSlot as never}
-          views={{
-            list: () => [
-              { id: 'chat', label: 'Chat' },
-              { id: 'trajectory', label: 'Trajectory' },
-            ],
-            subscribe: () => () => {},
-            version: () => 1,
-          }}
+          views={views}
           open={open}
           t={t}
         />
@@ -173,14 +178,7 @@ function mount(
           useStore={bindSnapshotSelector(chat)}
           actions={chat.actions}
           renderSlot={renderSlot as never}
-          views={{
-            list: () => [
-              { id: 'chat', label: 'Chat' },
-              { id: 'trajectory', label: 'Trajectory' },
-            ],
-            subscribe: () => () => {},
-            version: () => 1,
-          }}
+          views={views}
           releaseSessionImages={vi.fn()}
           bindDraftMirror={write => wiring.bindMirror(write)}
         />
@@ -442,6 +440,26 @@ describe('ConversationRoot resident composer', () => {
     expect(b.view.getByRole('textbox')).toBeTruthy()
   })
 
+  it('keeps the Chat fallback selected by id when a view is inserted before it', () => {
+    const viewTabs: ViewTab[] = [
+      { id: 'chat', label: 'Chat' },
+      { id: 'trajectory', label: 'Trajectory' },
+    ]
+    const b = mount(conversationSnapshot(), undefined, undefined, { viewTabs })
+    // A removed dynamic view leaves its persisted id behind. The visible
+    // fallback is Chat and must stay Chat when another lower-order view lands.
+    act(() => { b.chat.actions.setView('removed-view') })
+    expect(b.view.getByTestId('view-chat')).toBeTruthy()
+
+    viewTabs.unshift({ id: 'new-view', label: 'New view' })
+    b.rerender()
+
+    expect(b.view.getByTestId('view-chat')).toBeTruthy()
+    expect(b.view.queryByTestId('view-new-view')).toBeNull()
+    expect(b.view.getByRole('tab', { name: 'Chat' }).getAttribute('aria-selected')).toBe('true')
+    expect(b.view.getByRole('tab', { name: 'New view' }).getAttribute('aria-selected')).toBe('false')
+  })
+
   it('rolls the pending workspace label back when switching fails', async () => {
     const selectWorkspace = vi.fn(async () => { throw new Error('connect failed') })
     const b = mount(