refactor(gui): dissolve the tool ring into per-view keyed slots

Four rounds of structural rework on the conversation surface, converging
on one registration model for the whole client:

- Review fixes: open() leaves the inject factory (SessionsService owns
  the semantic); ConversationService mounts via ctx.plugin(); the
  bespoke view registry retires into the 'conversation.view' list slot.
- Ring alignment: createChatView factory retired (components get
  everything through checkable shares at the register call site); the
  hand-rolled t/i18n threading is deleted wholesale — a future
  framework-level i18n will supply t as a standard prop keyed by slot
  name, so no interim manual channel.
- Toolview dissolution: ToolViewRegistry / ToolViewResolver /
  ToolViewOutlet / ctx.toolviews retire. Tool rows are entries of the
  'conversation.chat.toolview' keyed slot (scope: session) declared by
  the chat entry; ToolRowOwnerProps is the unified owner payload;
  GenericToolCard becomes the call-site fallback; registrants are plain
  plugins (inject ['slots','conversation'] as the load-order seam);
  session-dimension dispatch moves into components (useSessions reads
  parentId); trajectory/waterfall gain same-shape slots the day they
  render tool rows (RendersCheck rejects empty declarations). Slot
  names mirror the composition path (<domain>.<entry>.<hole>).
- Staging follows current: cell()/binding() are pure resolution
  (render-safe); the constructor subscribes to the list store and
  followCurrent opens the event window when the current session
  changes — staging IS the open signal, business verbs are the timing,
  React render/commit is decoupled from window lifecycle. A masked
  current (projection gap) keeps the stage untouched so deferred
  teardown semantics survive reconnects.

Agent Note: .agents/notes/implemented/architecture/
2026-07-23-toolview-dissolution.md (bilingual pair) records the
decision, the four rejected alternatives, and the accepted semantic
changes; the web client architecture note and packages/client/AGENTS.md
carry the current-state narrative.

Verified: typecheck 0, duplication 0 clones (478 files), full coverage
run 6190 passed with zero threshold errors, knip 0, doc-sync 24/24,
client aggregate tsc 0, render-count checks (one commit per chunk, zero
row re-renders under streaming) green.

packages/client/ui-conversation/tests/chat-tool-row.spec.tsx

@@ -4,12 +4,11 @@ import { cleanup, fireEvent, render } from '@testing-library/react'
 
 afterEach(cleanup)
 import type { RunningToolCall, ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
-import type { UseSession } from '@deepseek-ai/dsh-client-ui-slots'
 import { classifyTool, toolRowModel } from '../src/client/contract/tool-call-model.ts'
 import { AssistantMarkdown } from '../src/client/chat/AssistantMarkdown.tsx'
 import { ToolRow } from '../src/client/chat/ToolRow.tsx'
 import { GenericToolCard } from '../src/client/chat/GenericToolCard.tsx'
-import type { ToolViewProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
+import type { ToolRowOwnerProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
 
 const running = (over?: Partial<RunningToolCall>): RunningToolCall => ({
   callId: 'c1', name: 'bash', argsRaw: '{"command":"ls -la","description":"List files"}',
@@ -139,11 +138,8 @@ describe('ThinkRow', () => {
 })
 
 describe('GenericToolCard', () => {
-  const props = (toolName: string, block: RunningToolCall | ToolResultNode): ToolViewProps => ({
-    callId: 'c1', toolName, block,
-    useSession: (() => { throw new Error('unused') }) as unknown as UseSession,
-    actions: { openDetails: vi.fn() },
-    t: (k) => k,
+  const props = (toolName: string, block: RunningToolCall | ToolResultNode): ToolRowOwnerProps => ({
+    callId: 'c1', toolName, block, openDetails: vi.fn(),
   })
 
   it('renders the classified variant row from the frozen slice', () => {
@@ -188,10 +184,10 @@ describe('GenericToolCard', () => {
     expect(view.container.querySelector('svg')).not.toBeNull()
   })
 
-  it('row click reaches actions.openDetails', () => {
+  it('row click reaches openDetails', () => {
     const p = props('bash', result())
     const view = render(<GenericToolCard {...p} />)
     fireEvent.click(view.getByText('List files'))
-    expect(p.actions.openDetails).toHaveBeenCalledTimes(1)
+    expect(p.openDetails).toHaveBeenCalledTimes(1)
   })
 })