diff --git a/.changeset/boot-hydration-scoped-lookup.md b/.changeset/boot-hydration-scoped-lookup.md
new file mode 100644
index 0000000000..b8d0993269
--- /dev/null
+++ b/.changeset/boot-hydration-scoped-lookup.md
@@ -0,0 +1,30 @@
+---
+"@objectstack/metadata-protocol": patch
+---
+
+fix(metadata-protocol): boot hydration grafts each overlay row's protection envelope from ITS OWN package (#4624)
+
+`loadMetaFromDb` (boot hydration) kept a **third** inline copy of the
+overlay→SchemaRegistry registration rule, and its artifact lookup was
+**unscoped** — the exact pre-#1828 shape ADR-0048 removed from `getMetaItems`:
+with two installed packages shipping the same `type`/`name`, a name-colliding
+overlay row grafted the **first-registered** package's
+`_lock`/`_lockReason`/`_packageId`/`_provenance` onto another package's row at
+every kernel boot. A row customized under package B could come up wearing
+package A's identity and lock.
+
+The non-object branch now delegates to the ONE shared
+`hydrateOverlayIntoRegistry` (introduced by #4521 for the read-side hydration
+and the write-through), passing the row's own `package_id` — one rule, one
+implementation, and the ADR-0048 package-scoped lookup applies at boot exactly
+as it does on read and write.
+
+No other boot behaviour changes:
+
+- **Boot order** — when packaged artifacts have not loaded yet at hydration
+  time, the scoped lookup finds nothing, exactly like the unscoped one did,
+  and the row registers unchanged.
+- **Package-less (global) rows** — `package_id IS NULL` keeps the legacy
+  best-effort first-match graft, identical to the read-side hydration.
+- **Row selection** — the helper carries no environment gate; which rows
+  `loadMetaFromDb` loads is decided by its query, unchanged here.
diff --git a/packages/metadata-protocol/src/protocol.ts b/packages/metadata-protocol/src/protocol.ts
index 26eeb81beb..74700afe2b 100644
--- a/packages/metadata-protocol/src/protocol.ts
+++ b/packages/metadata-protocol/src/protocol.ts
@@ -8960,17 +8960,23 @@ export class ObjectStackProtocolImplementation implements
                             record.packageId || 'sys_metadata',
                         );
                     } else {
-                        // Same envelope graft as the getMetaItems hydration:
-                        // the plain-key entry shadows any packaged artifact,
-                        // so carry the artifact's `_lock`/`_packageId`/
-                        // `_provenance` along (ADR-0010 §3.3). When artifacts
-                        // load after this hydration the merge finds nothing
-                        // and the row registers unchanged — same as before.
-                        const artifact = this.lookupArtifactItem(normalizedType, (data as any)?.name);
-                        this.engine.registry.registerItem(
+                        // Same rule as the getMetaItems read-side hydration and
+                        // the #4521 write-through — the ONE shared
+                        // {@link hydrateOverlayIntoRegistry}: graft the
+                        // artifact's protection envelope (ADR-0010 §3.3) with
+                        // the artifact lookup scoped to the row's OWN package
+                        // (ADR-0048 / #1828 / #4624). Pre-fix this branch kept
+                        // a third inline copy that looked the artifact up
+                        // UNSCOPED, so a name-colliding overlay grafted the
+                        // first-registered package's `_lock`/`_packageId`/
+                        // `_provenance` onto another package's row at boot.
+                        // When artifacts load after this hydration the merge
+                        // finds nothing and the row registers unchanged — same
+                        // as before, scoped or not.
+                        this.hydrateOverlayIntoRegistry(
                             normalizedType,
-                            mergeArtifactProtection(data, artifact) as any,
-                            'name' as any,
+                            data,
+                            (record as { package_id?: string | null }).package_id ?? undefined,
                         );
                     }
                     loaded++;
diff --git a/packages/objectql/src/protocol-boot-hydration-scoped.test.ts b/packages/objectql/src/protocol-boot-hydration-scoped.test.ts
new file mode 100644
index 0000000000..4c9f372dab
--- /dev/null
+++ b/packages/objectql/src/protocol-boot-hydration-scoped.test.ts
@@ -0,0 +1,176 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * #4624 — boot hydration (`loadMetaFromDb`) grafts each overlay row's
+ * protection envelope from ITS OWN package (ADR-0048 / #1828).
+ *
+ * Pre-fix, the non-object branch of `loadMetaFromDb` kept a third inline
+ * copy of the overlay→SchemaRegistry rule and looked the artifact up
+ * UNSCOPED (`lookupArtifactItem(type, name)` without the row's
+ * `package_id`) — the exact pre-#1828 shape: with two installed packages
+ * shipping the same `type`/`name`, a name-colliding overlay row grafted
+ * the FIRST-registered package's `_lock`/`_packageId`/`_provenance` onto
+ * another package's row at boot (composite-scan first-match by Map
+ * iteration order).
+ *
+ * Post-fix the branch delegates to the ONE shared
+ * `hydrateOverlayIntoRegistry` (#4521), so the ADR-0048 package-scoped
+ * lookup applies at boot exactly as it does on the read-side hydration
+ * and the write-through.
+ */
+
+import { describe, it, expect } from 'vitest';
+import { ObjectStackProtocolImplementation } from '@objectstack/metadata-protocol';
+import { SchemaRegistry } from './registry.js';
+
+const PKG_A = 'com.acme.a';
+const PKG_B = 'com.acme.b';
+
+function artifactPage(pkg: string, label: string) {
+    return {
+        name: 'home',
+        label,
+        _packageId: pkg,
+        _packageVersion: '1.0.0',
+        _provenance: 'package',
+        _lock: 'full',
+        _lockReason: `Locked by ${pkg}`,
+    };
+}
+
+interface Row {
+    id: string;
+    type: string;
+    name: string;
+    organization_id: string | null;
+    package_id: string | null;
+    state: string;
+    metadata: string;
+}
+
+function makeEngine(registry: SchemaRegistry, rows: Row[]) {
+    const matches = (r: Row, where: Record<string, unknown>): boolean => {
+        for (const [k, v] of Object.entries(where)) {
+            if (v === undefined) continue;
+            if ((r as any)[k] !== v) return false;
+        }
+        return true;
+    };
+    const engine: any = {
+        registry,
+        async find(_t: string, opts: { where: Record<string, unknown> }) {
+            return rows.filter((r) => matches(r, opts.where));
+        },
+        async findOne(_t: string, opts: { where: Record<string, unknown> }) {
+            return rows.find((r) => matches(r, opts.where)) ?? null;
+        },
+        async insert() { return { id: 'x' }; },
+        async update() { return { id: 'x' }; },
+        async delete() { return { deleted: 0 }; },
+    };
+    return engine;
+}
+
+function overlayRow(partial: Partial<Row> & { name: string; metadata: unknown }): Row {
+    return {
+        id: `r_${partial.name}_${partial.package_id ?? 'global'}`,
+        type: 'page',
+        organization_id: null,
+        package_id: null,
+        state: 'active',
+        ...partial,
+        metadata: typeof partial.metadata === 'string'
+            ? partial.metadata
+            : JSON.stringify(partial.metadata),
+    } as Row;
+}
+
+describe('loadMetaFromDb — ADR-0048 package-scoped protection graft at boot (#4624)', () => {
+    it('grafts the envelope from the row\'s OWN package, not the first-registered one', async () => {
+        const registry = new SchemaRegistry({ multiTenant: false });
+        registry.logLevel = 'silent';
+        // Package A registers FIRST — pre-fix, the unscoped composite scan
+        // returned A for every same-named row, whatever package owned it.
+        registry.registerItem('page', artifactPage(PKG_A, 'A Home'), 'name', PKG_A);
+        registry.registerItem('page', artifactPage(PKG_B, 'B Home'), 'name', PKG_B);
+
+        const rows = [
+            overlayRow({
+                name: 'home',
+                package_id: PKG_B,
+                metadata: { name: 'home', label: 'B Home (customized)' },
+            }),
+        ];
+        const engine = makeEngine(registry, rows);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        const res = await protocol.loadMetaFromDb();
+        expect(res.loaded).toBe(1);
+        expect(res.errors).toBe(0);
+
+        // The hydrated plain-key entry carries package B's envelope —
+        // pre-fix it carried PKG_A's (`_packageId: 'com.acme.a'`,
+        // `_lockReason: 'Locked by com.acme.a'`).
+        const direct: any = registry.getItem('page', 'home');
+        expect(direct.label).toBe('B Home (customized)'); // overlay content wins
+        expect(direct._packageId).toBe(PKG_B);
+        expect(direct._lock).toBe('full');
+        expect(direct._lockReason).toBe(`Locked by ${PKG_B}`);
+        expect(direct._provenance).toBe('package');
+    });
+
+    it('registers the row unchanged when artifacts have not loaded yet (boot-order no-op)', async () => {
+        // Empty registry at hydration time — the scoped lookup finds
+        // nothing, exactly like the unscoped one did, and the row
+        // registers without a grafted envelope. Artifact-after-hydration
+        // boot orders are unaffected by the scoping.
+        const registry = new SchemaRegistry({ multiTenant: false });
+        registry.logLevel = 'silent';
+        const rows = [
+            overlayRow({
+                name: 'home',
+                package_id: PKG_B,
+                metadata: { name: 'home', label: 'B Home (customized)' },
+            }),
+        ];
+        const engine = makeEngine(registry, rows);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        const res = await protocol.loadMetaFromDb();
+        expect(res.loaded).toBe(1);
+
+        const direct: any = registry.getItem('page', 'home');
+        expect(direct.label).toBe('B Home (customized)');
+        expect(direct._lock).toBeUndefined();
+        expect(direct._packageId).toBeUndefined();
+        expect(direct._provenance).toBeUndefined();
+    });
+
+    it('keeps the legacy best-effort graft for package-less (global) rows', async () => {
+        // A row with no package binding keeps the pre-existing unscoped
+        // first-match semantics — identical to the read-side hydration.
+        const registry = new SchemaRegistry({ multiTenant: false });
+        registry.logLevel = 'silent';
+        registry.registerItem('page', artifactPage(PKG_A, 'A Home'), 'name', PKG_A);
+        registry.registerItem('page', artifactPage(PKG_B, 'B Home'), 'name', PKG_B);
+
+        const rows = [
+            overlayRow({
+                name: 'home',
+                package_id: null,
+                metadata: { name: 'home', label: 'Global overlay' },
+            }),
+        ];
+        const engine = makeEngine(registry, rows);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        await protocol.loadMetaFromDb();
+
+        const direct: any = registry.getItem('page', 'home');
+        expect(direct.label).toBe('Global overlay');
+        // Best-effort first-match: SOME package's envelope is grafted
+        // (legacy behaviour, unchanged by #4624 — do not over-pin which).
+        expect([PKG_A, PKG_B]).toContain(direct._packageId);
+        expect(direct._lock).toBe('full');
+    });
+});