feat(objectql): publish the registry's three conflict error codes as importable constants

`NamespaceConflictError`, `ArtifactObjectNameConflictError` and
`ObjectOwnershipConflictError` each already tell the reader to identify them by
`code` rather than `instanceof`, and offered nothing to import. Convert the
three inline literals to exported `*_CODE` constants on the shape the six
existing constants in this package already use, and re-export them from the
package barrel.

The strings are byte-identical to the literals they replace: this moves where a
spelling lives, never what it says.

The three rows in `packages/runtime/src/dispatcher-error-vocabulary.ts` move
from `shape: 'classfield'` to `shape: 'classconst'` — measured, not assumed:
`check:dispatcher-error-vocabulary` reconciles in both directions and went red
with 3 stale-row plus 3 unclassified-site findings until the rows were updated.
The site census is unchanged at 66/66 classified either side.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ARYe3yQTQCUFm5qPYNgKaJ

Author: claude

.changeset/registry-conflict-code-constants.md

@@ -0,0 +1,19 @@
+---
+"@objectstack/objectql": minor
+---
+
+The registry's three conflict refusals now publish their error `code` as an importable constant.
+
+`SchemaRegistry`'s install-time and registration refusals each already told the reader, in their own docblocks, to identify them by `code` rather than `instanceof` — and offered nothing to import. `NAMESPACE_CONFLICT`, `DUPLICATE_ARTIFACT_OBJECT_NAME` and `OBJECT_OWNERSHIP_CONFLICT` were inline string literals, so the only way to follow that instruction was to re-spell the string in the consumer's own package, which acquires a `check:error-code-provenance` stamp site there and can then drift from what the engine throws with no compile error to say so.
+
+Three new exports from `@objectstack/objectql`:
+
+- `NAMESPACE_CONFLICT_CODE` — the ADR-0048 Phase 1 install-time namespace gate's refusal.
+- `DUPLICATE_ARTIFACT_OBJECT_NAME_CODE` — the ADR-0130 D3 one-artifact object-name refusal.
+- `OBJECT_OWNERSHIP_CONFLICT_CODE` — the ADR-0029 D3 single-owner-per-object-name refusal.
+
+**Why `code` and not `instanceof`.** This package declares both realms in its own `exports` (`import` reaches `dist/index.mjs`, `require` reaches `dist/index.js`), so a consumer holding the other realm's copy of a class gets `instanceof` === false — measured, and silent. A `code` compare is the check that survives crossing that boundary.
+
+**Nothing about the wire changed.** Each constant holds text byte-identical to the literal it replaces; the refusals throw the same `code`, the same `status: 422` and the same message as before. Existing consumers that spell the string themselves keep working unchanged — this adds an affordance, it removes nothing.
+
+**The error classes stay unexported, deliberately.** Publishing them would publish the `instanceof` route this convention exists to replace.

packages/objectql/src/index.ts

@@ -66,6 +66,24 @@ export {
 } from './registry.js';
 export type { InjectedColumnProvenance } from './registry.js';
 
+// [#16159] The three ADR-0112 `code` strings the registry's install-time and
+// registration refusals carry, as constants a consumer can import instead of
+// re-spelling. Exported for the reason #14936 established and measured: this
+// package declares BOTH realms in its own `exports`, so a consumer holding
+// the other realm's copy of a class gets `instanceof` === false, silently —
+// a `code` compare is the only check that survives the split, and these are
+// how a consumer performs it without authoring the string itself (and so
+// without acquiring a `check:error-code-provenance` stamp site of its own).
+// ⛔ The classes themselves stay unexported deliberately: exporting them
+// would publish the `instanceof` route this convention exists to replace.
+// See the shared docblock over the constants in `registry.ts` for the full
+// reasoning and for why the `*_CODE` spelling is load-bearing.
+export {
+  NAMESPACE_CONFLICT_CODE,
+  DUPLICATE_ARTIFACT_OBJECT_NAME_CODE,
+  OBJECT_OWNERSHIP_CONFLICT_CODE,
+} from './registry.js';
+
 // [#14553] The navigation-contribution group diagnostic (ADR-0029 D7,
 // ADR-0112 D6c). Exported because `os build` is the SECOND door that has to
 // answer "does this group id resolve?" — over a composed artifact, at compile

packages/objectql/src/registry-conflict-code-constants.test.ts

@@ -0,0 +1,107 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * #16159 — the registry's three conflict refusals publish their ADR-0112
+ * `code` as an importable constant.
+ *
+ * ## What this pins, and why each assertion is here
+ *
+ * `NamespaceConflictError`, `ArtifactObjectNameConflictError` and
+ * `ObjectOwnershipConflictError` each already told the reader, in their own
+ * docblocks, to identify them by `code`. Until this change the code was an
+ * inline string literal, so the only way to follow that instruction was to
+ * RE-SPELL it in the consumer's package — which acquires a
+ * `check:error-code-provenance` stamp site there and can drift from what this
+ * engine throws with no compile error to say so.
+ *
+ * Four facts, each its own case so a failure reads as the specific regression:
+ *
+ *   1. each constant holds the exact wire string. Spelled literally HERE on
+ *      purpose: the test layer is outside `check:error-code-provenance`'s
+ *      scanned population, so pinning it costs no stamp site while making a
+ *      silent rename of a published code impossible to pass off as "still the
+ *      same code". ⛔ This is the byte-identity fence the card asked for — the
+ *      conversion moves where a spelling lives, never what it says.
+ *   2. the constant IS the code the thrown refusal carries, asserted together
+ *      with `status`. ⛔ Never a bare `toThrow()`: #14367 measured on this very
+ *      path that a throw-shaped assertion stayed GREEN with the install-time
+ *      check one layer up ablated, because a second refusal fired one step
+ *      later and was indistinguishable to `toThrow()`.
+ *   3. the constants are reachable from the package BARREL. This is the whole
+ *      affordance the card buys — a constant a consumer cannot import is not
+ *      an answer to "catch it by `code`" — and it is what a re-export deleted
+ *      by a future barrel edit would lose silently.
+ *   4. a `code` compare matches a foreign-realm copy of the refusal where
+ *      `instanceof` returns false. THE CONTROL, and the reason the convention
+ *      exists (#14936): `@objectstack/objectql` declares both realms in its
+ *      own `exports`, so a consumer holding the other realm's copy gets
+ *      `instanceof` === false, silently. Without this case the others would
+ *      pass just as happily against an `instanceof`-based recommendation.
+ */
+
+import { describe, it, expect } from 'vitest';
+import {
+  NAMESPACE_CONFLICT_CODE,
+  DUPLICATE_ARTIFACT_OBJECT_NAME_CODE,
+  OBJECT_OWNERSHIP_CONFLICT_CODE,
+  NamespaceConflictError,
+  ArtifactObjectNameConflictError,
+  ObjectOwnershipConflictError,
+} from './registry.js';
+import * as barrel from './index.js';
+
+describe('#16159 the registry conflict codes are published constants', () => {
+  it('each constant holds the exact wire string it replaced', () => {
+    expect(NAMESPACE_CONFLICT_CODE).toBe('NAMESPACE_CONFLICT');
+    expect(DUPLICATE_ARTIFACT_OBJECT_NAME_CODE).toBe('DUPLICATE_ARTIFACT_OBJECT_NAME');
+    expect(OBJECT_OWNERSHIP_CONFLICT_CODE).toBe('OBJECT_OWNERSHIP_CONFLICT');
+  });
+
+  it('the constant IS the code the thrown namespace refusal carries, at its 422 status', () => {
+    const err = new NamespaceConflictError('crm', 'app.crm', 'app.other');
+    expect(err.code).toBe(NAMESPACE_CONFLICT_CODE);
+    expect(err.status).toBe(422);
+    // ADR-0112 D5's spelling, which is what a consumer holding the THROWN
+    // error reads out of the CLI `--json` envelope. Asserting only `status`
+    // would not notice these two drifting apart.
+    expect(err.httpStatus).toBe(422);
+  });
+
+  it('the constant IS the code the thrown artifact object-name refusal carries, at its 422 status', () => {
+    const err = new ArtifactObjectNameConflictError('crm_account', 'app.crm', 'app.other');
+    expect(err.code).toBe(DUPLICATE_ARTIFACT_OBJECT_NAME_CODE);
+    expect(err.status).toBe(422);
+    expect(err.httpStatus).toBe(422);
+  });
+
+  it('the constant IS the code the thrown ownership refusal carries, at its 422 status', () => {
+    const err = new ObjectOwnershipConflictError('crm_account', 'app.crm', 'app.other');
+    expect(err.code).toBe(OBJECT_OWNERSHIP_CONFLICT_CODE);
+    expect(err.status).toBe(422);
+    expect(err.httpStatus).toBe(422);
+  });
+
+  it('all three are re-exported from the package barrel, which is where a consumer reaches them', () => {
+    // Identity, not equality: a barrel that re-declared the string instead of
+    // re-exporting the constant would satisfy `toBe` on the VALUE while having
+    // re-introduced exactly the second spelling this card exists to remove.
+    expect(barrel.NAMESPACE_CONFLICT_CODE).toBe(NAMESPACE_CONFLICT_CODE);
+    expect(barrel.DUPLICATE_ARTIFACT_OBJECT_NAME_CODE).toBe(DUPLICATE_ARTIFACT_OBJECT_NAME_CODE);
+    expect(barrel.OBJECT_OWNERSHIP_CONFLICT_CODE).toBe(OBJECT_OWNERSHIP_CONFLICT_CODE);
+  });
+
+  it("a `code` compare matches the OTHER realm's copy — the exact case `instanceof` gets wrong", () => {
+    // What a consumer holding the other realm's copy of this module actually
+    // has: a structurally identical refusal from a DIFFERENT class object.
+    class NamespaceConflictErrorOtherRealmCopy extends Error {
+      readonly code = 'NAMESPACE_CONFLICT';
+      readonly status = 422;
+    }
+    const fromOtherRealm = new NamespaceConflictErrorOtherRealmCopy();
+
+    // THE CONTROL. Without this line the assertion below would pass against an
+    // `instanceof` recommendation too, i.e. against the defect.
+    expect(fromOtherRealm instanceof NamespaceConflictError).toBe(false);
+    expect(fromOtherRealm.code).toBe(NAMESPACE_CONFLICT_CODE);
+  });
+});

packages/objectql/src/registry.ts

@@ -1261,6 +1261,56 @@ function toRecordManifest(manifest: ObjectStackManifest): ObjectStackManifest {
   return out as ObjectStackManifest;
 }
 
+/**
+ * [#16159] The ADR-0112 `code` strings this file's three install-time and
+ * registration refusals carry, as constants a consumer can import.
+ *
+ * Every one of the three classes below already tells the reader, in its own
+ * docblock, that it "carries the ADR-0112 envelope (`code` + `status`)". That
+ * convention is sound and `instanceof` is not: `@objectstack/objectql`
+ * declares BOTH realms in its own `exports` (`import` reaches
+ * `dist/index.mjs`, `require` reaches `dist/index.js`), so a consumer holding
+ * the other realm's copy of a class gets `instanceof` === false — measured,
+ * and silent (#14936). A `code` compare is the check that survives crossing
+ * that boundary. Until now a consumer following the convention had to
+ * RE-SPELL the string itself, which acquires a `check:error-code-provenance`
+ * stamp site in the consumer's own package and can then drift from what this
+ * engine throws with no compile error to say so.
+ *
+ * ⛔ The strings are byte-identical to the literals they replace. This moves
+ * where a spelling lives, never what it says; renaming any of these codes is
+ * a separate breaking decision and never a rider on this conversion.
+ *
+ * The `*_CODE` NAME is load-bearing rather than cosmetic, in two gates at
+ * once: it is the shape `check:error-code-provenance`'s `constdef` pattern
+ * can see, and `readonly code = X_CODE;` is the shape
+ * `check:dispatcher-error-vocabulary` classifies as `classconst` (the three
+ * rows in `packages/runtime/src/dispatcher-error-vocabulary.ts` move from
+ * `classfield` to `classconst` with this change, and the scanner resolves the
+ * constant back to the same value). ⛔ Never rename out of that shape to
+ * quiet a gate: a spelling a gate cannot see is the failure mode the gate
+ * exists to catch, not a clean result.
+ *
+ * Shape and placement follow the six `*_CODE` constants already in this
+ * package (`DUPLICATE_RECORD_CODE`, `HOOK_TARGET_REBIND_ERROR_CODE`,
+ * `HOOK_UNSCOPED_DATA_ACCESS_CODE`,
+ * `MULTI_UPDATE_HOOK_KEY_DIVERGENCE_CODE`, `EMPTY_CREDENTIAL_REFUSAL_CODE`,
+ * `SYSTEM_WRITE_ORGANIZATION_REQUIRED_CODE`) — re-exported from the
+ * `index.ts` barrel and, like all six, deliberately NOT from the lean
+ * `core.ts` entry, which carries none of them.
+ *
+ * ⛔ Deliberately NOT a recognizer factory: #16156 measured that a
+ * `makeRecognizer(code)` signature still requires every call site to supply
+ * the code, which RELOCATES the literal rather than removing it.
+ */
+export const NAMESPACE_CONFLICT_CODE = 'NAMESPACE_CONFLICT' as const;
+
+/** {@link ArtifactObjectNameConflictError}'s code — ADR-0130 D3, one artifact. */
+export const DUPLICATE_ARTIFACT_OBJECT_NAME_CODE = 'DUPLICATE_ARTIFACT_OBJECT_NAME' as const;
+
+/** {@link ObjectOwnershipConflictError}'s code — ADR-0029 D3, single owner per name. */
+export const OBJECT_OWNERSHIP_CONFLICT_CODE = 'OBJECT_OWNERSHIP_CONFLICT' as const;
+
 /**
  * Raised when a package is installed whose `manifest.namespace` is already owned
  * by a **different** installed package in this installation (ADR-0048 Phase 1).
@@ -1289,7 +1339,7 @@ function toRecordManifest(manifest: ObjectStackManifest): ObjectStackManifest {
  * already correct and specific.
  */
 export class NamespaceConflictError extends Error {
-  readonly code = 'NAMESPACE_CONFLICT';
+  readonly code = NAMESPACE_CONFLICT_CODE;
   readonly status = 422;
   /** The same number under ADR-0112 D5's spelling — what a consumer holding the THROWN error reads (the CLI `--json` envelope). `status` stays for the HTTP doors, which read it. */
   readonly httpStatus = 422;
@@ -1403,7 +1453,7 @@ function declaredOwnedObjectNames(manifest: ObjectStackManifest): string[] {
  * repository's rejection tests assert against, never a bare throw.
  */
 export class ArtifactObjectNameConflictError extends Error {
-  readonly code = 'DUPLICATE_ARTIFACT_OBJECT_NAME';
+  readonly code = DUPLICATE_ARTIFACT_OBJECT_NAME_CODE;
   readonly status = 422;
   /** The same number under ADR-0112 D5's spelling — what a consumer holding the THROWN error reads (the CLI `--json` envelope). `status` stays for the HTTP doors, which read it. */
   readonly httpStatus = 422;
@@ -1464,7 +1514,7 @@ export class ArtifactObjectNameConflictError extends Error {
  * nothing is refused there.
  */
 export class ObjectOwnershipConflictError extends Error {
-  readonly code = 'OBJECT_OWNERSHIP_CONFLICT';
+  readonly code = OBJECT_OWNERSHIP_CONFLICT_CODE;
   readonly status = 422;
   /** The same number under ADR-0112 D5's spelling — what a consumer holding the THROWN error reads (the CLI `--json` envelope). `status` stays for the HTTP doors, which read it. */
   readonly httpStatus = 422;

packages/runtime/src/dispatcher-error-vocabulary.ts

@@ -624,7 +624,11 @@ export const UNREGISTERED_CODE_SITES: readonly UnregisteredCodeSite[] = [
     {
         code: 'NAMESPACE_CONFLICT',
         file: 'packages/objectql/src/registry.ts',
-        shape: 'classfield',
+        // [#16159] `classconst`, not `classfield`, since the literal became the
+        // exported `NAMESPACE_CONFLICT_CODE` constant in the producer. The VALUE is
+        // byte-identical and the scanner resolves the constant back to it; only the
+        // spelling the scan matches on moved. The verdict below is untouched.
+        shape: 'classconst',
         door: 'dispatcher',
         verdict: 'pending-registration',
         why:
@@ -884,7 +888,11 @@ export const UNREGISTERED_CODE_SITES: readonly UnregisteredCodeSite[] = [
     {
         code: 'DUPLICATE_ARTIFACT_OBJECT_NAME',
         file: 'packages/objectql/src/registry.ts',
-        shape: 'classfield',
+        // [#16159] `classconst`, not `classfield`, since the literal became the
+        // exported `DUPLICATE_ARTIFACT_OBJECT_NAME_CODE` constant in the producer. The VALUE is
+        // byte-identical and the scanner resolves the constant back to it; only the
+        // spelling the scan matches on moved. The verdict below is untouched.
+        shape: 'classconst',
         door: 'none',
         verdict: 'boot-refusal',
         why:
@@ -912,7 +920,11 @@ export const UNREGISTERED_CODE_SITES: readonly UnregisteredCodeSite[] = [
     {
         code: 'OBJECT_OWNERSHIP_CONFLICT',
         file: 'packages/objectql/src/registry.ts',
-        shape: 'classfield',
+        // [#16159] `classconst`, not `classfield`, since the literal became the
+        // exported `OBJECT_OWNERSHIP_CONFLICT_CODE` constant in the producer. The VALUE is
+        // byte-identical and the scanner resolves the constant back to it; only the
+        // spelling the scan matches on moved. The verdict below is untouched.
+        shape: 'classconst',
         door: 'none',
         verdict: 'boot-refusal',
         why: