diff --git a/.github/actions/flybot-tests/action.yml b/.github/actions/flybot-tests/action.yml
index acd2b0c7c..9008493f4 100644
--- a/.github/actions/flybot-tests/action.yml
+++ b/.github/actions/flybot-tests/action.yml
@@ -38,6 +38,15 @@ runs:
       env:
         DSH: ${{ inputs.dsh }}
       run: npm run harness -- --no-save "@deepseek-ai/dsh@$DSH"
+    # A part handoff moves a task by rewriting a private DSH row (`service.serialize` +
+    # `(await service.getDomain()).table('tasks')`), and no unit test can see the real package there: a
+    # rename would turn into one rt.warn and the task would silently stay on the archived part (#1257).
+    # So the shape is pinned right after the harness installs it — the same step a DSH upgrade changes.
+    - name: dsh-schedule private task row shape (#1257)
+      shell: bash
+      env:
+        DSH_HARNESS: ${{ github.workspace }}/core/dev/harness
+      run: node .github/scripts/check-dsh-task-shape.mjs
     - name: Fetch origin/main for arch-docs check
       shell: bash
       run: |
diff --git a/.github/scripts/check-dsh-task-shape.mjs b/.github/scripts/check-dsh-task-shape.mjs
new file mode 100644
index 000000000..f08c6f218
--- /dev/null
+++ b/.github/scripts/check-dsh-task-shape.mjs
@@ -0,0 +1,151 @@
+// A part handoff moves a task by rewriting one row of DeepSeek Harness's schedule storage: `moveSchedules`
+// in core/src/host/schedules.js runs the write in `service.serialize(...)`, reads the row table through
+// `(await service.getDomain()).table('tasks')` and puts `{ ...task, sessionId: toId }` back (#1245).
+//
+// Both members are `private` in dsh-schedule's own typings (lib/types/index.d.ts: `private getDomain;`
+// and `private serialize;`), and the row belongs to a storage domain declared inside the package, so a
+// rename or a new row shape does not throw anywhere a test can see: the outer `catch` in `moveSchedules`
+// turns it into one `rt.warn`, the task stays on the part being archived, and the board simply stops
+// waking it. This is the check that goes red instead (#1257).
+//
+// It needs the real package, so it runs where a profile installs it: the DSH harness the unit tests
+// already use (`npm run harness` in core/, `DSH_HARNESS`). It fails rather than skips when the package or
+// a member is gone — a skip is not a pin. Only public exports are used: `ScheduleService`,
+// `scheduleDomain` and `createAtScheduleRecord`.
+//
+// What it does not open: the domain handle itself. `table(name)` lives on dsh-storage-domain's
+// DomainImpl, which that package does not export, and opening a real domain means booting the storage
+// facility with a backend. So the table name is pinned where it is declared instead — `scheduleDomain
+// .tables.tasks` must exist and its row schema must accept exactly the row moveSchedules writes.
+//
+// Usage: node .github/scripts/check-dsh-task-shape.mjs [harness-dir]
+import { existsSync, readFileSync } from 'node:fs'
+import { createRequire } from 'node:module'
+import { join, resolve } from 'node:path'
+import { pathToFileURL } from 'node:url'
+
+export const PACKAGE = '@deepseek-ai/dsh-schedule'
+
+// The row `moveSchedules` reads and writes, and the record members it reads off that row.
+export const ROW_MEMBERS = ['sessionId', 'record', 'status', 'deliveryHistory']
+export const RECORD_MEMBERS = ['id', 'title', 'kind', 'scheduledAt']
+export const STATUS_MEMBERS = ['active']
+
+export const REMEDY = [
+  'moveSchedules (core/src/host/schedules.js) writes one task row through the private members',
+  '  service.serialize(async () => { const tasks = (await service.getDomain()).table(\'tasks\'); ... })',
+  `and the row shape {${ROW_MEMBERS.join(', ')}} whose record carries {${RECORD_MEMBERS.join(', ')}}`,
+  `with status values {${STATUS_MEMBERS.join(', ')}} (dsh-schedule 0.2.x keeps getDomain and serialize private).`,
+  'Both members and that row shape are private on the DSH side: when DSH is upgraded, re-confirm this',
+  'path (and this check) before bumping the harness pin in core/dev/harness/package.json. A rename here',
+  'does not throw where anyone sees it — it leaves every moved task on the part being archived behind',
+  'one rt.warn, and the board stops waking it with no red anywhere.',
+]
+
+// DSH_HARNESS is what the plugin and frontend suites already read; the harness directory is the fallback,
+// and it is the same order test/harness-resolve.mjs uses so a local run and CI resolve the same package.
+export function harnessDir(args = process.argv.slice(2)) {
+  const arg = args.find((value) => !value.startsWith('--'))
+  if (arg) return resolve(arg)
+  if (process.env.DSH_HARNESS) return resolve(process.env.DSH_HARNESS)
+  return resolve(import.meta.dirname, '..', '..', 'core', 'dev', 'harness')
+}
+
+// The package as a profile would load it: resolved from the harness, reported with its own version, so a
+// failure names the version whose shape moved rather than only the path it came from.
+export function loadSchedule(dir) {
+  if (!existsSync(dir)) throw new Error(`no harness at ${dir} (run \`npm run harness\` in core/ or set DSH_HARNESS)`)
+  const require = createRequire(pathToFileURL(join(dir, 'package.json')))
+  let manifest
+  try {
+    manifest = require.resolve(`${PACKAGE}/package.json`)
+  } catch {
+    throw new Error(`${PACKAGE} is not installed in the harness at ${dir} (run \`npm run harness\` in core/ or set DSH_HARNESS)`)
+  }
+  const version = JSON.parse(readFileSync(manifest, 'utf8')).version
+  const entry = require.resolve(PACKAGE)
+  return { version, entry, load: () => import(pathToFileURL(entry).href) }
+}
+
+// The task row the way moveSchedules leaves it: a frozen record from the package's own constructor, wrapped
+// in the row members it spreads.
+export const rowFor = (module, sessionId) => ({
+  sessionId,
+  record: module.createAtScheduleRecord('shape-pin', 'pin the DSH task row', '2027-01-01T00:00:00+00:00', Date.parse('2026-01-01T00:00:00Z'), 'Shape pin'),
+  status: 'active',
+  deliveryHistory: { records: [], earlierRecordsUnavailable: true },
+})
+
+// Every failure is one line naming what moved; an empty list is the pin holding.
+export function shapeProblems(module) {
+  const problems = []
+  const service = module.default
+  if (typeof service !== 'function') problems.push(`${PACKAGE} no longer default-exports ScheduleService`)
+  for (const member of ['getDomain', 'serialize']) {
+    if (typeof service?.prototype?.[member] !== 'function') problems.push(`ScheduleService.prototype.${member} is not a function`)
+  }
+  const value = module.scheduleDomain?.tables?.tasks?.valueSchema
+  if (typeof value?.parse !== 'function') {
+    problems.push(`scheduleDomain.tables.tasks.valueSchema is not a schema (the task row is not declared where moveSchedules reads it)`)
+    return problems
+  }
+  let row
+  try {
+    row = rowFor(module, 'session-from')
+  } catch (error) {
+    problems.push(`createAtScheduleRecord no longer builds the record a moved task carries: ${error?.message ?? error}`)
+    return problems
+  }
+  const missing = RECORD_MEMBERS.filter((member) => row.record?.[member] === undefined)
+  if (missing.length) problems.push(`a created record no longer carries ${missing.join(', ')}`)
+  let parsed
+  try {
+    parsed = value.parse(row)
+  } catch (error) {
+    problems.push(`the task row {${ROW_MEMBERS.join(', ')}} is refused by the schema: ${error?.issues?.map((issue) => `${issue.path?.join('.') ?? ''} ${issue.message}`).join('; ') ?? error?.message ?? error}`)
+    return problems
+  }
+  for (const member of ROW_MEMBERS.filter((name) => name !== 'sessionId')) {
+    if (parsed[member] === undefined) problems.push(`a parsed row comes back without ${member}`)
+  }
+  if (parsed.sessionId !== 'session-from') problems.push('a parsed row comes back with a different sessionId')
+  // Exactly what moveSchedules writes for the handoff: the row spread with the new session id.
+  try {
+    const moved = value.parse({ ...parsed, sessionId: 'session-to' })
+    if (moved.sessionId !== 'session-to') problems.push('a row spread with the new sessionId does not come back moved')
+  } catch (error) {
+    problems.push(`the row moveSchedules writes ({ ...task, sessionId }) is refused: ${error?.message ?? error}`)
+  }
+  // The members are only load-bearing if their names are: a row without sessionId, or with a status the
+  // move filter cannot see, has to be refused — otherwise this pin would pass on a free-form row.
+  const strict = (row) => value.safeParse(row).success
+  if (strict({ ...row, session: 'session-from' })) problems.push('a row renamed to {session} instead of {sessionId} is still accepted (the pin cannot see a rename)')
+  if (strict({ ...row, status: 'archived' })) problems.push('a row with status "archived" is still accepted (the filter moveSchedules applies reads {active})')
+  return problems
+}
+
+export function render({ version, entry, problems }) {
+  if (problems.length === 0) {
+    return `dsh-schedule task row: ok — ${PACKAGE}@${version} from ${entry}: getDomain/serialize present, {${ROW_MEMBERS.join(', ')}} accepted, record carries {${RECORD_MEMBERS.join(', ')}}`
+  }
+  return [
+    `dsh-schedule task row: FAIL — ${PACKAGE}@${version} from ${entry}`,
+    ...problems.map((problem) => `  - ${problem}`),
+    ...REMEDY,
+  ].join('\n')
+}
+
+if (process.argv[1] === import.meta.filename) {
+  let loaded
+  try {
+    loaded = loadSchedule(harnessDir())
+  } catch (error) {
+    console.error(`dsh-schedule task row: FAIL — ${error.message}`)
+    for (const line of REMEDY) console.error(`  ${line}`)
+    process.exit(1)
+  }
+  const module = await loaded.load()
+  const problems = shapeProblems(module)
+  console.log(render({ ...loaded, problems }))
+  if (problems.length > 0) process.exit(1)
+}