fix: canonicalize MCP watcher paths on Windows

Author: rockyshi1993

changelogs/releases/v1.20.4.md

@@ -7,6 +7,7 @@
 ## 变更
 
 - MCP supervisor 保持客户端已协商的 tools/prompts 契约；worker 重启时复核候选，schema 漂移给出明确重启错误。共享 JSONL reader 拒绝超大帧后继续接收合法请求。
+- MCP 文件监听使用实际物理目录，避免 Windows 短路径或 junction 别名触发原生监听断言并使 supervisor 退出。
 - 修正文件 inventory 截断、损坏 layout marker 的静默回退、正文或否定表述被误判为关闭，以及事务恢复的物理路径校验。
 - ContextRead bootstrap 复核 runtime/capability/catalog 身份，保留已消费的冲突记录；SkillRoute、文档和网站同步当前 87 Skill、84 active、3 gray。
 - 修复 managed validation 的短 lease 续租，按 task/shard owner 精确 CAS 更新并保持原 hard deadline；过期、撤销、换代和冲突 authority 仍拒绝。

mcp/hot-reload-supervisor.cjs

@@ -86,7 +86,10 @@ function watchTree (root, onChange) {
   const watchers = []
   const attach = (directory, recursive) => {
     try {
-      const watcher = fs.watch(directory, { recursive }, () => onChange())
+      // Windows notifications use the physical long path. A short-name or
+      // junction alias can otherwise trigger an uncatchable libuv assertion.
+      const watchDirectory = path.normalize(fs.realpathSync.native(directory))
+      const watcher = fs.watch(watchDirectory, { recursive }, () => onChange())
       watcher.on('error', () => onChange())
       watchers.push(watcher)
       return true

public-site/data/public-product-projection.json

@@ -1,6 +1,6 @@
 {
   "schemaVersion": "PublicProductProjectionV2",
-  "generatedAt": "2026-10-10T16:48:17.854Z",
+  "generatedAt": "2026-10-10T16:55:25.722Z",
   "release": {
     "version": "1.20.4"
   },

scripts/test-mcp-hot-reload-supervisor.js

@@ -75,6 +75,7 @@ async function main () {
   const tempRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'devcodex-mcp-hot-reload-'))
   const baseRoot = path.join(tempRoot, 'managed')
   const sourceRoot = path.join(tempRoot, 'source')
+  const sourceAlias = path.join(tempRoot, 'source-alias')
   const mcpRoot = path.join(sourceRoot, 'mcp')
   let child
   try {
@@ -91,6 +92,9 @@ async function main () {
     fs.rmSync(path.join(sourceRoot, '.git'), { recursive: true, force: true })
     fs.writeFileSync(path.join(sourceRoot, '.git'), 'gitdir: ../.git/worktrees/fixture\n')
     assert.strictEqual(validLiveSourceRoot(sourceRoot, 'profile'), true)
+    fs.symlinkSync(sourceRoot, sourceAlias, process.platform === 'win32' ? 'junction' : 'dir')
+    assert.strictEqual(validLiveSourceRoot(sourceAlias, 'profile'), true)
+    assert.strictEqual(fs.realpathSync.native(sourceAlias), fs.realpathSync.native(sourceRoot))
     const supervisor = path.join(baseRoot, 'mcp-hot-reload-supervisor.cjs')
     fs.copyFileSync(path.join(ROOT, 'mcp', 'hot-reload-supervisor.cjs'), supervisor)
     fs.writeFileSync(path.join(baseRoot, 'global-host-receipt.json'), `${JSON.stringify({
@@ -101,7 +105,7 @@ async function main () {
       runtimeSource: {
         schemaVersion: 'McpRuntimeSourceV1',
         mode: 'live-source-checkout',
-        sourceRoot
+        sourceRoot: sourceAlias
       },
       updatedAt: new Date().toISOString()
     })}\n`)
@@ -202,6 +206,7 @@ async function main () {
       newWorkerPid: second.pid,
       implementationHotReload: 'PASS',
       schemaChangeFallback: 'PASS',
+      physicalWatchPath: 'PASS',
       result: 'PASS'
     }))
   } finally {