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/service-orchestration.spec.ts

@@ -2,9 +2,10 @@
 /**
  * ConversationService orchestration half after the store-seat slimming:
  * scope-addressed send/cancel (result folding, root throw), the startSession
- * chain (create → sessions.open → scoped send), views ordering, and the
- * service-unavailable loud failures. Selection/draft state left this service
- * for the declared chat store (chat-store.spec.ts / selection-survival.spec.ts).
+ * chain (create → sessions.open → scoped send), and the service-unavailable
+ * loud failures. Selection/draft state left this service for the declared
+ * chat store (chat-store.spec.ts / selection-survival.spec.ts); the view
+ * registry left for the 'conversation.view' slot (views-type-chain.spec.tsx).
  */
 import { Context } from 'cordis'
 import { describe, expect, it, vi } from 'vitest'
@@ -68,7 +69,8 @@ async function bench(opts?: { sessions?: boolean }) {
     scope: (id: SessionId) => (id === sid('new-1') ? mint(id) : scopes.get(id)),
   } as unknown as SessionsService
   if (opts?.sessions !== false) ctx.provide('sessions', sessionsFake)
-  const fiber = ctx.plugin((pluginCtx) => { void new ConversationService(pluginCtx) })
+  // Class-plugin mount — the same form apply.ts uses in production.
+  const fiber = ctx.plugin(ConversationService)
   await fiber.await()
   const svc = ctx.get('conversation') as ConversationService
   const scopedSvc = (id: SessionId) => mint(id).get('conversation') as ConversationService
@@ -149,17 +151,3 @@ describe('service-unavailable loud failures', () => {
       .rejects.toThrow(/conversation service unavailable through the new scope/)
   })
 })
-
-describe('views ordering', () => {
-  it('orders by explicit order with undefined treated as zero (both comparator arms)', async () => {
-    const b = await bench()
-    const entry = (id: string, order?: number) => ({
-      id, label: id, component: () => null,
-      ...(order !== undefined ? { order } : {}),
-    })
-    b.svc.registerView(entry('z-late', 5) as never)
-    b.svc.registerView(entry('default-zero') as never)
-    b.svc.registerView(entry('first', -1) as never)
-    expect(b.svc.views().map(v => v.id)).toEqual(['first', 'default-zero', 'z-late'])
-  })
-})