fix: 严格对齐 ACP 协议实现到 stable v1 规范

对照 /Users/konghayao/code/knowledgebase/origin/acp 规范审计并修复 53 条合规性
发现（critical 5 / major 17 / minor 20 / nit 11），完整审计报告见
docs/acp-compliance-audit.md。

Agent 端 (src/services/acp/agent.ts):
- initialize() 补齐 authMethods，promptCapabilities.image 降级为 false（声明与
  实现脱节，按 initialization.mdx 不声明的 capability 视为不支持）
- sessionCapabilities.fork 移至 _meta.claudeCode.forkSession（fork 在
  meta.unstable.json 中，避免在 stable sessionCapabilities 中暴露 unstable 特性）
- unstable_resumeSession 传 replay:false，不再通过 session/update 重放历史
  （session-setup.mdx:239 明确禁止）
- PromptResponse.usage 移至 _meta.claudeCode.usage
  （extensibility.mdx:39 禁止在 spec 类型根添加自定义字段）
- 空字符串 prompt 改为显式 throw（不再误返 end_turn）

Bridge (src/services/acp/bridge.ts):
- 删除全部 usage_update discriminator（不在 stable v1 schema 中）
- 显式映射 refusal stop_reason（之前误报 end_turn）
- max_tokens / isError 检查互斥
- Read/Write/Edit/Glob 路径全部绝对化（协议规定路径 MUST 绝对）
- 补全 resource_link / resource ContentBlock 渲染

Permissions (src/services/acp/permissions.ts):
- 补齐 reject_always PermissionOption（schema 规定的四个 option 之一）
- checkTerminalOutput 优先检查标准 clientCapabilities.terminal，
  回退到 _meta.terminal_output
- 新增 onPermissionCancelled 回调：cancelled permission outcome →
  StopReason::Cancelled（schema.json:629）
- ExitPlanMode cancelled 分支补上 toolUseID 字段

PromptConversion (src/services/acp/promptConversion.ts):
- resource 分支处理 BlobResource（之前静默丢弃 blob 内容）

acp-link 代理 (packages/acp-link/src/):
- WS 协议从专有 {type, payload} 改造为标准 JSON-RPC 2.0
  （transports.mdx:52 要求自定义 transport MUST 保留 JSON-RPC 消息格式），
  同时向后兼容旧 envelope
- 实现 $/cancel_request 处理
- 使用 JSON-RPC 标准错误码 -32700 / -32600 / -32601 / -32602 / -32603
- capability / agentInfo / protocolVersion 完整透传

验证：bun run precheck 全部通过（tsc 零错误、biome ci 零警告、5841/5841 测试通过）；
ACP 专项测试 221/221 通过。独立 verification agent 抽查全部 PASS。

已知暂缓项（审计文档附录 B/C）：
- §3.5 traceparent/trace-context 传播（QueryEngine 无 header hook）
- §5.2 terminal/create 完整生命周期（P1，非阻断，需新 RPC 流程）
- §4.2 in_progress tool_call status（SHOULD 级）
- §8.8/8.9/8.14 stale types.ts（不在 owner 分配集合，runtime 已修正）

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/services/acp/permissions.ts

@@ -37,6 +37,15 @@ export function createAcpCanUseTool(
   cwd?: string,
   onModeChange?: (modeId: string) => void,
   isBypassModeAvailable?: () => boolean,
+  /**
+   * Invoked when the ACP client returns a `cancelled` permission outcome.
+   * The Agent uses this to set the session-level cancelled flag and interrupt
+   * the running query so session/prompt resolves with StopReason::Cancelled
+   * (schema.json:629) instead of treating the cancellation as a plain deny.
+   * Optional for backwards compatibility with callers that have not been
+   * wired up yet.
+   */
+  onPermissionCancelled?: () => void,
 ): CanUseToolFn {
   return async (
     tool: ToolType,
@@ -64,6 +73,7 @@ export function createAcpCanUseTool(
         cwd,
         onModeChange,
         isBypassModeAvailable,
+        onPermissionCancelled,
       )
     }
 
@@ -124,6 +134,11 @@ export function createAcpCanUseTool(
       { kind: 'allow_always', name: 'Always Allow', optionId: 'allow_always' },
       { kind: 'allow_once', name: 'Allow', optionId: 'allow' },
       { kind: 'reject_once', name: 'Reject', optionId: 'reject' },
+      {
+        kind: 'reject_always',
+        name: 'Always Reject',
+        optionId: 'reject_always',
+      },
     ]
 
     try {
@@ -134,10 +149,15 @@ export function createAcpCanUseTool(
       })
 
       if (response.outcome.outcome === 'cancelled') {
+        // Per schema.json:629, a cancelled permission outcome means the prompt
+        // turn was cancelled. Signal the session so prompt() resolves with
+        // StopReason::Cancelled instead of treating this as a normal denial.
+        onPermissionCancelled?.()
         return {
           behavior: 'deny',
           message: 'Permission request cancelled by client',
           decisionReason: { type: 'mode', mode: 'default' },
+          toolUseID,
         }
       }
 
@@ -181,6 +201,7 @@ async function handleExitPlanMode(
   cwd?: string,
   onModeChange?: (modeId: string) => void,
   isBypassModeAvailable?: () => boolean,
+  onPermissionCancelled?: () => void,
 ): Promise<PermissionAllowDecision | PermissionDenyDecision> {
   const options: Array<PermissionOption> = [
     {
@@ -229,6 +250,8 @@ async function handleExitPlanMode(
   })
 
   if (response.outcome.outcome === 'cancelled') {
+    // Propagate cancellation so prompt() resolves with StopReason::Cancelled.
+    onPermissionCancelled?.()
     return {
       behavior: 'deny',
       message: 'Tool use aborted',
@@ -279,6 +302,11 @@ async function handleExitPlanMode(
 
 function checkTerminalOutput(clientCapabilities?: ClientCapabilities): boolean {
   if (!clientCapabilities) return false
+  // Standard ACP v1 capability: ClientCapabilities.terminal (boolean).
+  if (clientCapabilities.terminal === true) return true
+  // Legacy Claude-Code clients advertised terminal support via _meta before
+  // the standard `terminal` boolean existed. `_meta` is reserved per the spec,
+  // but we keep this fallback for backward compatibility with older clients.
   const meta = (clientCapabilities as unknown as Record<string, unknown>)._meta
   if (!meta || typeof meta !== 'object') return false
   return (meta as Record<string, unknown>)['terminal_output'] === true