fix(metadata-core,service-cluster,create-objectstack): ESM-only subpaths declare their types under import (#26321)

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Part of #26206

Clause-②: no. Amended 20:45Z: split. This PR lands the three ESM-only
subpath groups (`Part of #26206`, non-breaking, types-only map changes
plus README lines). The driver-memory `default` retirement waits on an
ADR-0087 gate card (predicate 2 word-scans `default` across metadata
surfaces and can never certify that operand)
Metadata-protocol: none

## What changes

Three subpaths are ESM-only, and their export maps now say so. Each
subpath's `types` moved inside its `import` condition (`{ import: {
types, default } }`, the conditional shape #26198 / #26279 use). Each
package's README gets one paragraph saying the subpath is ESM-only.

| Entry | Before (`node16-cjs`) | Choice | Why |
|:---|:---|:---|:---|
| `@objectstack/metadata-core/testing` | `CJSResolvesToESM` | declared
ESM-only | It imports `vitest`, whose own `require()` entry throws
("Vitest cannot be imported in a CommonJS module using require()"), so a
CJS build could not load. Its `require` condition was already removed on
purpose (the tsup config's split-by-format comment). |
| `@objectstack/service-cluster/testing` | `CJSResolvesToESM` | declared
ESM-only | Same reason: it imports `vitest`. |
| `create-objectstack/created-summary` | `CJSResolvesToESM` | declared
ESM-only | Its one consumer is `@objectstack/cli`'s `init` (ESM). A CJS
build would add a `require` condition, which widens the accept set and
doesn't fit `Clause-②: no`. |
| `@objectstack/cli` `.` | `CJSResolvesToESM` | ESM-only, no manifest
change | See below. |
| `@objectstack/cli/console` | `CJSResolvesToESM` | ESM-only, no
manifest change | See below. |
| `@objectstack/cli/hook-body` | `CJSResolvesToESM` | ESM-only, no
manifest change | See below. |

For the first three, runtime behaviour does not change. `require()` of
each subpath already failed with `ERR_PACKAGE_PATH_NOT_EXPORTED`,
because the map carried `types` + `import` and no `require` or
`default`. The unconditional `types` was the inconsistency: TypeScript
under `node16`/`nodenext` still resolved the declarations for a CommonJS
caller, and attw reported that as `CJSResolvesToESM`. Now TypeScript
resolves them for `import` only, which is what Node does.

### `@objectstack/cli`: ESM-only, documented here (README follow-up)

The cli's three library entries (`.`, `./console`, `./hook-body`) map `{
types, default }` to ESM files, and they stay that way. Measured on Node
22.22.0, `require()` of all three works today through Node's
`require(esm)`. The `.` barrel loads every oclif command class.

- Any ESM-only map change (an `import`-only condition, or a `require`
stub that throws) would break those working `require()` callers. That's
a narrowing, and this card is `Clause-②: no`.
- A CJS build of the `.` barrel means a second build of the whole oclif
program, which is out of proportion for a p3.

So the attw `CJSResolvesToESM` items on these three stay, as intended
ESM-only entries: the files are ESM, and CommonJS callers reach them
through `import()` or Node's `require(esm)`. This card's claim kept
`packages/cli/README.md` out of scope while #26215 held it, so this
paragraph is the written declaration for now. **Follow-up:** add one
line to `packages/cli/README.md` saying `.`, `./console` and
`./hook-body` are ESM entries. #26215 has since merged, so nothing
blocks that line.

### Not in this PR: `@objectstack/driver-memory`'s default export

The card's driver-memory half (`FalseExportDefault`) is split out.
Nothing in this repository imports the default, which is the legacy `{
id, version, onEnable }` object the kernel never calls, so retiring it
is the right fix. But it retires a published export, and ADR-0087's
`runtime-export-retired` disposition cannot currently certify an operand
named `default`. Predicate 2 (no-metadata-surface) scans metadata
surfaces for the export's name and hits every `default:` key, starting
with `examples/app-crm/src/objects/account.object.ts`. The retirement
waits on that gate, so #26206 stays open for it.

## Evidence

attw 0.18.5 on `npm pack --ignore-scripts` of each package, built at
`6633075b` (before) and at this head (after):

| Package | Before | After |
|:---|:---|:---|
| `@objectstack/cli` | `CJSResolvesToESM` on `.`, `./console`,
`./hook-body` | unchanged (intended, see above) |
| `create-objectstack` | `CJSResolvesToESM` on `./created-summary` | 0
`CJSResolvesToESM` (`./created-summary` answers `NoResolution` under
`node16-cjs`, matching Node) |
| `@objectstack/metadata-core` | `CJSResolvesToESM` on `./testing` | 0
`CJSResolvesToESM` (`NoResolution` under `node16-cjs`) |
| `@objectstack/service-cluster` | `CJSResolvesToESM` on `./testing` | 0
`CJSResolvesToESM` (`NoResolution` under `node16-cjs`) |

`NoResolution` under `node10` on every subpath is unchanged and outside
the contract (legacy `node10` has no `exports` support).

Runtime probes, at this head:

- `import()` of all three subpaths resolves and loads.
- `require()` of all three still answers
`ERR_PACKAGE_PATH_NOT_EXPORTED`.
- `require()` of the three cli entries still loads.

## Acceptance notes

- Tests and typecheck ran at `fbc38f81`. That commit carries this head's
three map changes, plus the driver-memory half that `64128263` then
restored byte-for-byte to `main`.
- Tests (`pnpm --filter … run test`): metadata-core 823/823,
service-cluster 105/105, create-objectstack 269/269.
- Typecheck (`run typecheck`), green on 12 packages: the three changed
packages, plus every in-repo consumer of these subpaths. metadata-fs,
metadata-protocol, rest, runtime, service-cluster-redis and cli
(`init.ts`) are all ESM (`nodenext`, or `bundler` for test configs).
driver-memory, service-datasource and plugin-dev were covered for the
dropped half.
- `node scripts/check-adr-0087-registration.mjs --base origin/main` exit
0, with 1 non-breaking changeset seen. `node
scripts/check-changeset-no-major.mjs` exit 0.
- At `64128263`, all 71 `dispatch-gates --commands` families were run
locally, each exit captured before any pipe. `--ran` reconciliation: 71
derived, 71 run, 0 NOT-MEASURED. The list is in the report comment on
#26206.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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---
_Generated by [Claude
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---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: objectstack-fleet[bot]

.changeset/26206-cjs-entry-points.md

@@ -0,0 +1,12 @@
+---
+'@objectstack/metadata-core': patch
+'@objectstack/service-cluster': patch
+'create-objectstack': patch
+---
+
+fix(metadata-core,service-cluster,create-objectstack): ESM-only subpaths declare their types under `import`
+
+Clause-②: no
+Metadata-protocol: none
+
+`@objectstack/metadata-core/testing`, `@objectstack/service-cluster/testing` and `create-objectstack/created-summary` are ESM-only, and now say so in their export maps: the subpath's `types` moved inside its `import` condition. `require()` of these subpaths already failed at runtime with `ERR_PACKAGE_PATH_NOT_EXPORTED`. Before this change, TypeScript under `node16`/`nodenext` resolved their declarations for a CommonJS caller anyway (attw `CJSResolvesToESM`). Now it resolves them for `import` only, which is what Node does. ESM callers, and every resolution mode that reads the `import` condition, see no change. Each package's README now says the subpath is ESM-only.

packages/create-objectstack/README.md

@@ -105,6 +105,13 @@ npm run validate   # verify metadata: schema + predicates + bindings
 See the docs:
 [Your First Project](https://objectstack.ai/docs/getting-started/your-first-project).
 
+## Library subpath
+
+`create-objectstack/created-summary` (the "what was written" tree summary that
+`objectstack init` reuses) is **ESM-only**: the package is `"type": "module"`
+and the subpath declares only an `import` condition. Load it with `import`;
+`require()` is refused with `ERR_PACKAGE_PATH_NOT_EXPORTED`.
+
 ## License
 
 Apache-2.0. See [LICENSING.md](../../LICENSING.md).

packages/create-objectstack/package.json

@@ -10,8 +10,10 @@
   ],
   "exports": {
     "./created-summary": {
-      "types": "./dist/created-summary.d.ts",
-      "import": "./dist/created-summary.js"
+      "import": {
+        "types": "./dist/created-summary.d.ts",
+        "default": "./dist/created-summary.js"
+      }
     }
   },
   "scripts": {

packages/metadata-core/README.md

@@ -38,3 +38,8 @@ import {
 ```
 
 See ADR-0008 §2 for the full architectural rationale.
+
+`@objectstack/metadata-core/testing` (the repository contract suites) is
+**ESM-only**: it imports `vitest`, whose own `require()` entry throws, so
+the subpath declares only an `import` condition. Load it with `import`;
+`require()` is refused with `ERR_PACKAGE_PATH_NOT_EXPORTED`.

packages/metadata-core/package.json

@@ -19,8 +19,10 @@
       }
     },
     "./testing": {
-      "types": "./dist/testing.d.ts",
-      "import": "./dist/testing.js"
+      "import": {
+        "types": "./dist/testing.d.ts",
+        "default": "./dist/testing.js"
+      }
     }
   },
   "files": [

packages/services/service-cluster/README.md

@@ -7,3 +7,5 @@ import { ClusterServicePlugin } from '@objectstack/service-cluster';
 ```
 
 Documentation: [Cluster](https://objectstack.ai/docs/kernel/cluster)
+
+`@objectstack/service-cluster/testing` (the pub/sub, lock, KV and counter contract suites) is **ESM-only**: it imports `vitest`, whose own `require()` entry throws, so the subpath declares only an `import` condition. Load it with `import`; `require()` is refused with `ERR_PACKAGE_PATH_NOT_EXPORTED`.

packages/services/service-cluster/package.json

@@ -19,8 +19,10 @@
       }
     },
     "./testing": {
-      "types": "./dist/testing.d.ts",
-      "import": "./dist/testing.js"
+      "import": {
+        "types": "./dist/testing.d.ts",
+        "default": "./dist/testing.js"
+      }
     }
   },
   "scripts": {