fix: make managed SSH sessions fast and resilient

Managed SSH project selection repeatedly activated the remote Host and could
leave idle ACP bindings rejected as stale-controller after a controller
generation change. Host environment updates also coupled project state to
component installation evidence and presented a crowded control surface.

Project selection is now local-only, one Host connection serves compatible
project and conversation callers, idle bindings are safely replaced only
after proven controller takeover, and active prompts keep exact resume/replay.
Remote environment setup now uses explicit signed compound package
preparation with bounded transfer, rollback, recovery, and clearer settings.

Managed Hosts must be updated to separately distributed Agent 0.11.6 before
the daemon-side controller recovery fix takes effect. Desktop packages do not
embed the Agent or remote Runtime, and existing project data is preserved.

Release note: 托管 SSH 项目切换不再重复连接，同一 Host 可顺畅承载多个项目和对话；同时修复重连后的 stale-controller，并优化远程环境安装、更新与状态布局。

src/main/remote-agent/remote-environment-operation-store.test.ts

@@ -0,0 +1,68 @@
+import { mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, describe, expect, it } from 'vitest'
+import {
+  RemoteEnvironmentOperationStore,
+  type PendingRemoteEnvironmentOperation
+} from './remote-environment-operation-store'
+
+const temporaryDirectories: string[] = []
+const operation: PendingRemoteEnvironmentOperation = {
+  version: 1,
+  hostId: 'host-1',
+  targetIdentity: 'a'.repeat(64),
+  operationId: '00000000-0000-4000-8000-000000000777',
+  size: 123,
+  sha256: 'b'.repeat(64),
+  urls: []
+}
+
+afterEach(async () => {
+  await Promise.all(
+    temporaryDirectories.splice(0).map((path) =>
+      rm(path, { recursive: true, force: true })
+    )
+  )
+})
+
+describe('RemoteEnvironmentOperationStore', () => {
+  it('persists one bounded operation per Host and removes it', async () => {
+    const root = await mkdtemp(
+      join(tmpdir(), 'goodbuddy-environment-operation-')
+    )
+    temporaryDirectories.push(root)
+    const store = new RemoteEnvironmentOperationStore(root)
+
+    await store.save(operation)
+    await expect(store.load(operation.hostId)).resolves.toEqual(
+      operation
+    )
+    await store.remove(operation.hostId)
+    await expect(store.load(operation.hostId)).resolves.toBeUndefined()
+  })
+
+  it('rejects a mismatched or oversized recovery record', async () => {
+    const root = await mkdtemp(
+      join(tmpdir(), 'goodbuddy-environment-operation-')
+    )
+    temporaryDirectories.push(root)
+    const store = new RemoteEnvironmentOperationStore(root)
+    await store.save(operation)
+    const files = join(
+      root,
+      'remote-components',
+      'pending-environment-operations'
+    )
+    const { readdir } = await import('node:fs/promises')
+    const [record] = await readdir(files)
+    await writeFile(
+      join(files, record!),
+      Buffer.alloc(64 * 1024 + 1)
+    )
+
+    await expect(store.load(operation.hostId)).rejects.toThrow(
+      '超过大小限制'
+    )
+  })
+})