fix: reuse runtime processes across project sessions

Multiple projects could spawn duplicate heavyweight runtimes, while settings
changes and remote reconnection could cancel or strand native conversations.
Share compatible local OpenCode and DeepSeek Harness process owners and
Agent-owned ACP connections, retaining workspace routing, per-session modes,
model attribution, question ownership, targeted cancellation and idle cleanup.

Restore remote pending questions and terminal task projections across reconnect
and desktop restart, and preserve accepted ordinary requests during settings
replacement while cancelling expert-team parents with their replaced scheduler.
Extend regression coverage and Agent type checks. Record measured resource and
real-model validation results, including failures and limitations.

Also include the conversation media-generation design drafts (not an implemented
feature), documentation entry links and dedicated Linux test-directory guidance.
Desktop and Agent changes must be delivered together for shared process results.

Validation: typecheck and lint passed; staged content and documentation links
checked. Prior full regression and live-model evidence are recorded in progress
notes; no new full test suite or model calls were run for this commit.

Release note: 多项目会话现在复用兼容的 OpenCode 和 DeepSeek Harness 进程，减少重复启动并保持工作区、工具和取消隔离。修复远端问答在断线、重启及配置更新后的恢复与状态同步问题，Desktop 与 Agent 需配套更新。

src/main/agent/acp-remote-runtime.test.ts

@@ -20,6 +20,8 @@ import {
 import type { RuntimeEvent } from './runtime'
 import {
   AcpRemoteRuntime,
+  RemotePromptCancelledError,
+  RemotePromptRecoveryUnavailableError,
   type AcpRemoteRuntimeOptions
 } from './acp-remote-runtime'
 import type {
@@ -2979,6 +2981,42 @@ describe('AcpRemoteRuntime Agent-owned prompts', () => {
     expect(fixture.preparePrompt).toHaveBeenCalledOnce()
   })
 
+  it('uses the recovered generation for retained and new Sessions and mode changes', async () => {
+    const fixture = ownedChannel()
+    const fresh = ownedChannel()
+    try {
+      await collect(fixture.instance.run(
+        { ...request, workMode: 'ask' }, new AbortController().signal
+      ))
+      Object.defineProperty(fixture.channel, 'generation', { value: 2 })
+      await collect(fixture.instance.run(
+        { ...request, requestId: 'after-reconnect', workMode: 'execute' },
+        new AbortController().signal
+      ))
+      Object.defineProperty(fresh.channel, 'generation', { value: 2 })
+      await collect(fresh.instance.run(
+        { ...request, requestId: 'new-after-reconnect', conversationId: 'another-conversation' },
+        new AbortController().signal
+      ))
+      expect([
+        ...fixture.preparePrompt.mock.calls.slice(1),
+        ...fresh.preparePrompt.mock.calls
+      ].map(([prepared]) => ({
+        controllerGeneration: prepared.controllerGeneration,
+        connectionGeneration: prepared.connectionGeneration
+      }))).toEqual([
+        { controllerGeneration: 2, connectionGeneration: 2 },
+        { controllerGeneration: 2, connectionGeneration: 2 }
+      ])
+      expect(fixture.startOwnedPrompt).toHaveBeenNthCalledWith(
+        2, expect.objectContaining({ acpSessionId: 'owned-session' })
+      )
+      expect(fixture.attachOwnedPrompt).not.toHaveBeenCalled()
+    } finally {
+      await Promise.all([fixture.instance.dispose(), fresh.instance.dispose()])
+    }
+  })
+
   it('does not abandon an accepted Agent prompt for a later request', async () => {
     const fixture = ownedChannel({ waitForCancellation: true })
     const first = fixture.instance.run(
@@ -3115,6 +3153,30 @@ describe('AcpRemoteRuntime Agent-owned prompts', () => {
     expect(fixture.attachOwnedPrompt).not.toHaveBeenCalled()
   })
 
+  it('definitively ends recovery after the original Agent installation is replaced', async () => {
+    const fixture = ownedChannel({ waitForCancellation: true })
+    const first = fixture.instance.run(request, new AbortController().signal)
+    await first.next()
+    await first.return()
+    const channelFactory = vi.fn(async () => fixture.channel)
+    const replacement = factoryRuntime(channelFactory, fixture.store, {
+      identity: { ...identity, agentInstallationId: 'replacement-agent' },
+      modelBridgePolicy,
+      modelProfile: ownedModelProfile
+    })
+    try {
+      await expect(collect(replacement.run(
+        { ...request, remoteRecoveryOnly: true },
+        new AbortController().signal
+      ))).rejects.toBeInstanceOf(RemotePromptRecoveryUnavailableError)
+      expect(channelFactory).not.toHaveBeenCalled()
+      expect(fixture.startOwnedPrompt).toHaveBeenCalledOnce()
+      expect(fixture.attachOwnedPrompt).not.toHaveBeenCalled()
+    } finally {
+      await Promise.all([replacement.dispose(), fixture.instance.dispose()])
+    }
+  })
+
   it('reconciles an owned cancellation before the next prompt in the same conversation', async () => {
     const fixture = ownedChannel()
     fixture.pageOwnedPromptTranscript.mockImplementationOnce(() => new Promise<never>(() => {}))
@@ -3124,7 +3186,7 @@ describe('AcpRemoteRuntime Agent-owned prompts', () => {
     const pending = stream.next()
     await vi.waitFor(() => expect(fixture.pageOwnedPromptTranscript).toHaveBeenCalledOnce())
     controller.abort(new Error('cancel pending question'))
-    await expect(pending).rejects.toThrow('cancel pending question')
+    await expect(pending).rejects.toBeInstanceOf(RemotePromptCancelledError)
     expect(await fixture.store.getByConversation(request.conversationId)).toBeUndefined()
     const events = await collect(fixture.instance.run(
       { ...request, requestId: 'after-cancel' }, new AbortController().signal
@@ -3170,7 +3232,7 @@ describe('AcpRemoteRuntime Agent-owned prompts', () => {
     expect(settled).toBe(false)
 
     releaseEscalation()
-    await expect(pending).rejects.toThrow('cancel owned prompt')
+    await expect(pending).rejects.toBeInstanceOf(RemotePromptCancelledError)
   })
 
   it.each([