feat(telemetry): anonymous user id from $DSH_HOME/.userid, reported as OTel Resource user.id

session-telemetry-otel owns the identity as its own module (src/user-id.ts):
getOrCreateAnonymousUserId() returns the bare UUID line in $DSH_HOME/.userid,
minting a random UUID v4 on first use — synchronous IO with a process-lifetime
memo keyed by resolved path, an exclusive-create (wx) settle for concurrent
first launches, best-effort on read-only homes, and deletion resetting the
identity on the next launch by design.

The backend carries the id as the Resource's user.id (the OTel semconv user
attribute), once per export batch alongside service.name/service.version.
The identity belongs to the OTel feed alone; the dsh-sdk launcher telemetry
keeps its own separate store.

packages/telemetry/session-telemetry-otel/tests/otel.spec.ts

@@ -5,11 +5,15 @@
  * for the default-exported Service class.
  */
 
-import { afterEach, describe, expect, it } from 'vitest'
+import { afterAll, afterEach, beforeAll, describe, expect, it } from 'vitest'
 import { createServer, type Server } from 'node:http'
 import { once } from 'node:events'
+import { mkdtempSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
 import { gunzipSync } from 'node:zlib'
 import { Context } from 'cordis'
+import { getOrCreateAnonymousUserId } from '../src/user-id.ts'
 import Loader from '@cordisjs/plugin-loader'
 import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
 import TelemetryOtel, { Config } from '../src/index.ts'
@@ -37,6 +41,21 @@ interface OtlpLogsRequest {
 
 const servers: Server[] = []
 
+// The backend resolves the harness home's anonymous user id at construction;
+// pin DSH_HOME to a temp dir so the suite never touches the ambient ~/.dsh.
+let tempHome: string
+let previousDshHome: string | undefined
+beforeAll(() => {
+  tempHome = mkdtempSync(join(tmpdir(), 'dsh-otel-home-'))
+  previousDshHome = process.env.DSH_HOME
+  process.env.DSH_HOME = tempHome
+})
+afterAll(() => {
+  if (previousDshHome === undefined) delete process.env.DSH_HOME
+  else process.env.DSH_HOME = previousDshHome
+  rmSync(tempHome, { recursive: true, force: true })
+})
+
 afterEach(async () => {
   for (const server of servers.splice(0)) {
     server.close()
@@ -104,6 +123,7 @@ describe('TelemetryOtel wire', () => {
 
     const resource = first.body.resourceLogs[0]!.resource.attributes
     expect(resource).toContainEqual({ key: 'service.name', value: { stringValue: 'deepseek-harness' } })
+    expect(resource).toContainEqual({ key: 'user.id', value: { stringValue: getOrCreateAnonymousUserId() } })
 
     const records = allRecords(captures)
     const ledger = records.filter(r => r.scope === '@deepseek-ai/dsh-session-telemetry-otel')

packages/telemetry/session-telemetry-otel/tests/user-id.spec.ts

@@ -0,0 +1,107 @@
+import { chmodSync, existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, describe, expect, it } from 'vitest'
+import {
+  USER_ID_FILE_NAME,
+  getOrCreateAnonymousUserId,
+} from '../src/user-id.ts'
+
+const dirs: string[] = []
+
+function tempHome(): string {
+  const dir = mkdtempSync(join(tmpdir(), 'dsh-userid-'))
+  dirs.push(dir)
+  return dir
+}
+
+afterEach(() => {
+  for (const dir of dirs.splice(0)) {
+    chmodSync(dir, 0o700)
+    rmSync(dir, { recursive: true, force: true })
+  }
+})
+
+const UUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
+
+describe('getOrCreateAnonymousUserId', () => {
+  it('creates, persists, and returns a bare UUID line on first use', () => {
+    const home = tempHome()
+    const id = getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })
+    expect(id).toMatch(UUID)
+    expect(readFileSync(join(home, USER_ID_FILE_NAME), 'utf8')).toBe(`${id}\n`)
+  })
+
+  it('creates the home directory when missing', () => {
+    const home = join(tempHome(), 'nested', 'home')
+    const id = getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })
+    expect(readFileSync(join(home, USER_ID_FILE_NAME), 'utf8')).toBe(`${id}\n`)
+  })
+
+  it('returns the persisted id on subsequent calls, tolerating surrounding whitespace', () => {
+    const home = tempHome()
+    const existing = '01234567-89ab-4cde-8f01-23456789abcd'
+    writeFileSync(join(home, USER_ID_FILE_NAME), `  ${existing}\n\n`, 'utf8')
+    expect(getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })).toBe(existing)
+  })
+
+  it('overwrites a corrupt file with a fresh id', () => {
+    const home = tempHome()
+    writeFileSync(join(home, USER_ID_FILE_NAME), 'not-a-uuid\n', 'utf8')
+    const id = getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })
+    expect(id).toMatch(UUID)
+    expect(readFileSync(join(home, USER_ID_FILE_NAME), 'utf8')).toBe(`${id}\n`)
+  })
+
+  it('adopts a concurrent winner: exclusive create loses to an id written after the initial read', () => {
+    const home = tempHome()
+    const winner = 'aaaaaaaa-bbbb-4ccc-8ddd-eeeeeeeeeeee'
+    const file = join(home, USER_ID_FILE_NAME)
+    // The generator seam runs between the initial read (absent) and the wx
+    // write, so planting the winner here simulates the concurrent first launch.
+    const id = getOrCreateAnonymousUserId({
+      env: { DSH_HOME: home },
+      randomUUID: () => {
+        writeFileSync(file, `${winner}\n`, 'utf8')
+        return 'ffffffff-0000-4000-8000-000000000000'
+      },
+    })
+    expect(id).toBe(winner)
+  })
+
+  it('returns a usable id when the home is unwritable, without persisting', () => {
+    const home = tempHome()
+    const blocked = join(home, 'blocked')
+    mkdirSync(blocked)
+    chmodSync(blocked, 0o500)
+    const id = getOrCreateAnonymousUserId({ env: { DSH_HOME: blocked } })
+    expect(id).toMatch(UUID)
+    expect(existsSync(join(blocked, USER_ID_FILE_NAME))).toBe(false)
+  })
+
+  it('memoizes per resolved home for the process lifetime: one read, deletion-proof', () => {
+    const home = tempHome()
+    const first = getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })
+    rmSync(join(home, USER_ID_FILE_NAME))
+    expect(getOrCreateAnonymousUserId({ env: { DSH_HOME: home } })).toBe(first)
+  })
+
+  it('keeps distinct homes on distinct ids', () => {
+    const a = getOrCreateAnonymousUserId({ env: { DSH_HOME: tempHome() } })
+    const b = getOrCreateAnonymousUserId({ env: { DSH_HOME: tempHome() } })
+    expect(a).not.toBe(b)
+  })
+
+  it('reads process.env by default', () => {
+    const home = tempHome()
+    const previous = process.env.DSH_HOME
+    process.env.DSH_HOME = home
+    try {
+      const id = getOrCreateAnonymousUserId()
+      expect(readFileSync(join(home, USER_ID_FILE_NAME), 'utf8')).toBe(`${id}\n`)
+    } finally {
+      if (previous === undefined) delete process.env.DSH_HOME
+      else process.env.DSH_HOME = previous
+    }
+  })
+})