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+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#29985 codemod] The "Data CRUD" facet of
+ * `ObjectStackProtocolImplementation`: the bodies of `probeRecord` moved out of
+ * `protocol.ts` whole by `scripts/codemod-split-protocol.mjs`.
+ *
+ * A MOVE, not a redesign. `ProtocolDataCrudFacet` is a stateless facet over the host
+ * (ruling 6624345766): each static method below is the body of the class
+ * member of the same name as `packages/metadata-protocol/scripts/host-split.mjs`
+ * moves one (ruling E, item E1), with `this.<member>` read as `host.<member>`
+ * and nothing else changed. The facet holds no state: the fields stay on the
+ * class, and a body reaches them through the host (`protocol-host.ts`).
+ *
+ * The class keeps every member as a one-line delegation. A public member
+ * keeps its docblock there, which the published `.d.ts` prints; a private
+ * member's docblock moved here with its body (docblock ownership).
+ *
+ * What a body reads from elsewhere, it imports from where `protocol.ts`
+ * imports it. Nothing re-exports this module, so the published surface does
+ * not move.
+ */
+
+import type { ProtocolHost } from './protocol-host.js';
+
+export class ProtocolDataCrudFacet {
+    /**
+     * [#4435] Does this row EXIST? A fact about the database — deliberately
+     * NOT "may this caller see it".
+     *
+     * Read with a system context so no row-level policy narrows it. That is
+     * load-bearing, and the first version of this fix got it wrong: probing
+     * with the CALLER's context turns the existence gate into an authorization
+     * gate, because a row the caller cannot read comes back `null` and the
+     * PATCH answers 404. Two things break when it does.
+     *
+     * 1. It silently changes RLS semantics. Whether an unreadable row may be
+     *    written by id is the #1994 pre-image check's decision, made inside
+     *    `engine.update` where the write policy lives. A probe in front of it
+     *    quietly adds a second, different rule — scope creep into the security
+     *    model, from a bug fix about missing records.
+     *
+     * 2. It disarms a revert-provable security proof. `@proof: rls-by-id-write`
+     *    (`packages/qa/dogfood/test/rls-fixture.dogfood.test.ts`, referenced by
+     *    the `permission.rowLevelSecurity.using` liveness ledger entry) boots a
+     *    fixture whose member can read nothing but has no write policy, and
+     *    asserts the runner reports `rls-hole`. A caller-scoped probe 404s that
+     *    PATCH, so the RED half goes green — and the gate can no longer prove
+     *    it is able to go red. If the #1994 fix were ever reverted, this probe
+     *    would MASK it. Accidentally hardening one path is not worth
+     *    permanently blinding the gate that watches the whole class.
+     *
+     * So the probe answers existence only, and authorization stays exactly
+     * where it was. The one behaviour this adds is the 404 the issue asked for:
+     * an id that names no row at all.
+     *
+     * ⛔ And what it finds never answers IN FRONT of the write's
+     * authorization. Its readers are OCC's `updated_at` comparison, asked only
+     * when the caller sent a token ({@link assertVersionMatch}) and answering
+     * only for a row the caller's own read returns ({@link assertVersionOf}),
+     * and the by-id update's existence check, asked only after `engine.update`
+     * has judged and resolved the write (`updateData`, and the bulk faces
+     * through {@link assertRecordExists}) — so an update by id answers the same
+     * refusal whether or not the id exists, as delete does. With a mismatched
+     * token, a caller whose read of the row is refused gets that read refusal.
+     */
+    static async probeRecord(host: Pick<ProtocolHost, 'engine'>, object: string, id: string): Promise<any> {
+        return host.engine.findOne(object, { where: { id }, context: { isSystem: true } });
+    }
+}
@@ -0,0 +1,166 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#29985 codemod] The "Global search and the metadata cache" facet of
+ * `ObjectStackProtocolImplementation`: the bodies of `getMetaItemCached` moved
+ * out of `protocol.ts` whole by `scripts/codemod-split-protocol.mjs`.
+ *
+ * A MOVE, not a redesign. `ProtocolSearchAndCacheFacet` is a stateless facet over the host
+ * (ruling 6624345766): each static method below is the body of the class
+ * member of the same name as `packages/metadata-protocol/scripts/host-split.mjs`
+ * moves one (ruling E, item E1), with `this.<member>` read as `host.<member>`
+ * and nothing else changed. The facet holds no state: the fields stay on the
+ * class, and a body reaches them through the host (`protocol-host.ts`).
+ *
+ * The class keeps every member as a one-line delegation. A public member
+ * keeps its docblock there, which the published `.d.ts` prints; a private
+ * member's docblock moved here with its body (docblock ownership).
+ *
+ * What a body reads from elsewhere, it imports from where `protocol.ts`
+ * imports it. Nothing re-exports this module, so the published surface does
+ * not move.
+ */
+
+import type { FlowRegistration, MetadataCacheRequest, MetadataCacheResponse } from '@objectstack/spec/api';
+import { canonicalizeMetaRequestType } from './protocol-meta-type-schema.js';
+import { simpleHash } from './protocol-version-tokens.js';
+import { metadataItemNotFoundError } from './protocol-client-failures.js';
+import type { ProtocolHost } from './protocol-host.js';
+
+export class ProtocolSearchAndCacheFacet {
+    /** The body of `ObjectStackProtocolImplementation#getMetaItemCached`; the method's docblock there is its contract. */
+    static async getMetaItemCached(host: Pick<ProtocolHost, 'getMetaItem'>, request: { type: string, name: string, cacheRequest?: MetadataCacheRequest, locale?: string }): Promise<MetadataCacheResponse & { registration?: FlowRegistration; disabledActions?: string[]; cascadeDeleteObjects?: string[] }> {
+        // #4432 — CANONICAL TYPE KEY. See {@link canonicalMetaType}. The ETag
+        // and the cache entry are keyed by type, so two spellings would cache
+        // the same item twice and invalidate only one of them.
+        request = canonicalizeMetaRequestType(request);
+        try {
+            // Delegate to getMetaItem so the customization-overlay read order
+            // (sys_metadata → registry → MetadataService) is honoured here too
+            // (ADR-0005). Without this, cached reads silently bypass overlays.
+            const result = await host.getMetaItem({
+                type: request.type,
+                name: request.name,
+            });
+            const item = (result as any)?.item;
+            // [#23316] The automation engine's verdict on a flow, as the
+            // delegate read above just resolved it — live, on every call. It
+            // rides beside `data` for the REST layer's default door, and is
+            // never hashed into the ETag below (see the 304 note there).
+            const registration = (result as { registration?: FlowRegistration } | undefined)?.registration;
+            // [#27842] …and, for an object, the packaged actions the activation
+            // ledger switches off, on exactly those terms: live, beside `data`,
+            // never hashed (see the 304 note below).
+            const disabledActions = (result as { disabledActions?: string[] } | undefined)?.disabledActions;
+            // [#28001] …and the objects a delete of one of its records can
+            // cascade into, on the same terms.
+            const cascadeDeleteObjects = (result as { cascadeDeleteObjects?: string[] } | undefined)?.cascadeDeleteObjects;
+
+            if (!item) {
+                // [#5532] Structured: 404 + the catalog's `RESOURCE_NOT_FOUND`.
+                // Reaching here now means a real miss — `getMetaItem` throws
+                // 503 rather than answering `undefined` when the store could
+                // not be read (see
+                // {@link rethrowUnlessMetadataStoreUnprovisioned}) — so the
+                // 404 is a claim this layer is finally entitled to make.
+                //
+                // [#5840] That entitlement was only three-quarters earned when
+                // it was written: it held for the `sys_metadata` overlay read,
+                // whose failure arrives as a throw, and NOT for the
+                // MetadataService read, whose failure `MetadataManager`
+                // warn-logs and skips — so a loader outage still reached this
+                // line as a plain missing `item` and was answered 404. Both
+                // halves now refuse to guess (see
+                // {@link readItemFromMetadataService}).
+                throw metadataItemNotFoundError(request.type, request.name);
+            }
+
+            // Calculate ETag (simple hash of the stringified metadata).
+            //
+            // The ETag MUST vary by locale. The REST layer translates the
+            // response body *after* this validator check, so an ETag computed
+            // only from the (untranslated) content would let a language switch
+            // match the prior `If-None-Match` and return `304 Not Modified`
+            // carrying a stale-locale body — labels/headers stuck in the old
+            // language until a hard refresh (issue #1319). Folding the resolved
+            // locale into the hash gives each locale a distinct validator.
+            //
+            // [ADR-0131 D6] No organization is part of the validator: the
+            // read is the environment's for every caller, so the document
+            // hashed below is the whole scope. An org-less caller's validator
+            // is byte-for-byte the one it was issued before.
+            //
+            // ⛔ The ONE invariant this block depends on: `content` — the bytes
+            // actually being sent — is inside the hash below. A 304 is answered
+            // only on an exact match over those bytes, so a caller is only ever
+            // pinned to the representation IT received. Hashing anything
+            // cheaper than the document — a version marker — destroys that
+            // silently.
+            const content = JSON.stringify(item);
+            const scope = [
+                request.locale || undefined,
+            ].filter((part): part is string => part !== undefined);
+            const hash = simpleHash(
+                scope.length > 0
+                    ? `${scope.join('\u0000')}\u0000${content}`
+                    : content,
+            );
+            const etag = { value: hash, weak: false };
+
+            // Check If-None-Match header
+            //
+            // [#23316] …except for a read that carries `registration`: the
+            // served body holds the engine's verdict and this validator does
+            // not (it hashes the document alone, and the verdict stays out of
+            // it), so a 304 here would pin the caller to the verdict it was
+            // served before — after the engine re-registered or refused the
+            // flow under an unchanged body. Such a read is always answered in
+            // full; the work is the same either way, since this method always
+            // performs the delegate read.
+            //
+            // [#27842] The same holds for `disabledActions`: an administrator's
+            // switch moves no byte of the object document, so a 304 would keep
+            // the caller on the switched-off list it was served before.
+            // [#28001] So does `cascadeDeleteObjects`: an object registered
+            // later that cascades into this one moves no byte of it either.
+            if (
+                request.cacheRequest?.ifNoneMatch
+                && registration === undefined && disabledActions === undefined && cascadeDeleteObjects === undefined
+            ) {
+                const clientEtag = request.cacheRequest.ifNoneMatch.replace(/^"(.*)"$/, '$1').replace(/^W\/"(.*)"$/, '$1');
+                if (clientEtag === hash) {
+                    // Return 304 Not Modified
+                    return {
+                        notModified: true,
+                        etag,
+                    };
+                }
+            }
+
+            // Return full metadata with cache headers
+            return {
+                data: item,
+                ...(registration !== undefined ? { registration } : {}),
+                ...(disabledActions !== undefined ? { disabledActions } : {}),
+                ...(cascadeDeleteObjects !== undefined ? { cascadeDeleteObjects } : {}),
+                etag,
+                lastModified: new Date().toISOString(),
+                cacheControl: {
+                    // Metadata is invalidated by publish, so freshness must be
+                    // gated by the ETag validator — not a TTL. `no-cache` lets
+                    // clients store the body but forces an `If-None-Match`
+                    // revalidation on every use: a cheap 304 when unchanged,
+                    // fresh fields the instant a publish bumps the ETag. The old
+                    // `max-age=3600` pinned the schema for up to an hour, so the
+                    // AI-build "New" form kept rendering pre-publish fields until
+                    // the TTL lapsed (no revalidation in between). `private` also
+                    // keeps per-tenant metadata out of shared CDN/proxy caches.
+                    directives: ['private', 'no-cache'],
+                },
+                notModified: false,
+            };
+        } catch (error: any) {
+            throw error;
+        }
+    }
+}