diff --git a/README.md b/README.md
index bddd034..7cc936d 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,16 @@ catalog bytes with:
 node scripts/validate-catalog.mjs --strict-envelope
 ```
 
+Local `check:signature` uses `--candidate`: it verifies the historical envelope
+signature and permits changed source bytes only at a greater Store sequence.
+Exact already-signed bytes also pass. Production publication and the signing
+dry-run keep strict byte-equality validation.
+
+Store and Package Index have independent catalog sequences. Store catalog 14
+reconciles discovery with the already-published Package Index catalog 13;
+it does not rewrite that release or its BOM. The reconciliation fixture records
+both sequences and the downloaded Package Index catalog/BOM hashes.
+
 ## Key rotation
 
 Rotate the signing key as a coordinated change: add the new public key and
diff --git a/catalog.json b/catalog.json
index 2457338..e2e3b5b 100644
--- a/catalog.json
+++ b/catalog.json
@@ -1,8 +1,8 @@
 {
   "schema_version": 1,
-  "sequence": 13,
-  "issued_at": "2026-08-30T00:00:00Z",
-  "expires_at": "2027-08-29T00:00:00Z",
+  "sequence": 14,
+  "issued_at": "2026-09-04T23:17:36Z",
+  "expires_at": "2027-09-04T23:17:36Z",
   "listings": [
     {
       "id": "com.kosmos.shell",
@@ -44,7 +44,7 @@
       "categories": ["productivity", "accessibility"],
       "availability": { "platforms": ["windows"] },
       "data_compatibility": [],
-      "distribution": { "package_id": "com.kosmos.dictation", "version": "0.2.2" },
+      "distribution": { "package_id": "com.kosmos.dictation", "version": "0.2.3" },
       "connects_to": null,
       "icon_url": "https://github.com/makekosmos/store/releases/download/store-assets-1/dictation-0.2.0.png",
       "screenshots": []
diff --git a/package.json b/package.json
index 654158b..5728fd4 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
   "scripts": {
     "prepare": "node scripts/install-hooks.mjs",
     "test": "node --test scripts/*.test.mjs",
-    "check:signature": "node scripts/validate-catalog.mjs --strict-envelope && bun run test && node scripts/dry-run.mjs && node --check scripts/sign-catalog.mjs && node --check scripts/check-release-sequence.mjs",
+    "check:signature": "node scripts/validate-catalog.mjs --candidate && bun run test && node scripts/dry-run.mjs && node --check scripts/sign-catalog.mjs && node --check scripts/check-release-sequence.mjs",
     "check": "bun run check:signature"
   }
 }
diff --git a/scripts/fixtures/package-index-release.v1.json b/scripts/fixtures/package-index-release.v1.json
index 9462275..4c89853 100644
--- a/scripts/fixtures/package-index-release.v1.json
+++ b/scripts/fixtures/package-index-release.v1.json
@@ -1,7 +1,11 @@
 {
-  "store_sequence": 13,
+  "store_sequence": 14,
+  "package_index_sequence": 13,
+  "package_index_catalog_sha256": "3f2675135a976f874d612344b9c7b4d75922a128dc614426bad41683b530bafd",
+  "package_index_release_bom_sha256": "772d5c673d0e2bb9b98a266a04b508ea9d772735d4aa8034ae55ade07732773b",
   "packages": {
     "com.kosmos.arcadia": "0.1.8",
+    "com.kosmos.dictation": "0.2.3",
     "com.kosmos.agenda": "0.2.4",
     "com.kosmos.memoria": "0.6.3"
   }
diff --git a/scripts/validate-catalog.mjs b/scripts/validate-catalog.mjs
index 841a20e..f5448ec 100644
--- a/scripts/validate-catalog.mjs
+++ b/scripts/validate-catalog.mjs
@@ -150,6 +150,12 @@ export function validateCatalog(catalog, envelope, options = {}) {
   assert(envelope, "committed envelope is required");
   const envelopeResult = validateEnvelope(envelope, options);
   if (options.strictEnvelope) assert(envelopeResult.payload.sequence === result.sequence, "catalog and envelope sequences differ");
+  if (options.candidate) {
+    assert(options.catalogBytes, "candidate validation requires catalog bytes");
+    const matches = Buffer.compare(envelopeResult.bytes, options.catalogBytes) === 0;
+    assert(matches || result.sequence > envelopeResult.payload.sequence,
+      "an unsigned catalog candidate must advance the signed sequence");
+  }
   return result;
 }
 
@@ -159,7 +165,11 @@ async function main() {
   const catalogBytes = await readFile(catalogPath);
   const catalog = JSON.parse(catalogBytes);
   const envelope = JSON.parse(await readFile(envelopePath, "utf8"));
-  const result = validateCatalog(catalog, envelope, { strictEnvelope: process.argv.includes("--strict-envelope"), catalogBytes });
+  const result = validateCatalog(catalog, envelope, {
+    strictEnvelope: process.argv.includes("--strict-envelope"),
+    candidate: process.argv.includes("--candidate"),
+    catalogBytes,
+  });
   console.log(`Validated catalog sequence ${result.sequence} with ${result.listings} listings.`);
 }
 
diff --git a/scripts/validate-catalog.test.mjs b/scripts/validate-catalog.test.mjs
index 5c5bfa4..5568469 100644
--- a/scripts/validate-catalog.test.mjs
+++ b/scripts/validate-catalog.test.mjs
@@ -60,7 +60,7 @@ test("strict mode rejects stale reviewed bytes", () => {
   }), /bytes do not match/);
 });
 
-test("catalog versions match the package-index release anchor", () => {
+test("Store candidate reconciles versions with the published Package Index catalog", () => {
   assert.equal(catalog.sequence, packageIndexRelease.store_sequence);
   for (const [packageId, version] of Object.entries(packageIndexRelease.packages)) {
     const listing = catalog.listings.find((item) => item.id === packageId);
@@ -68,3 +68,30 @@ test("catalog versions match the package-index release anchor", () => {
     assert.equal(listing.distribution.version, version);
   }
 });
+
+test("candidate accepts a new sequence while preserving the historical signature", () => {
+  const bytes = Buffer.from(JSON.stringify(catalog));
+  assert.equal(validateCatalog(catalog, envelope, { candidate: true, catalogBytes: bytes }).sequence, 14);
+  assert.throws(() => validateCatalog(catalog, envelope, { strictEnvelope: true, catalogBytes: bytes }), /bytes do not match/);
+});
+
+test("candidate rejects same-sequence changes and rollback", () => {
+  const previous = JSON.parse(Buffer.from(envelope.bytes, "base64"));
+  for (const sequence of [previous.sequence, previous.sequence - 1]) {
+    const candidate = { ...catalog, sequence };
+    assert.throws(() => validateCatalog(candidate, envelope, {
+      candidate: true, catalogBytes: Buffer.from(JSON.stringify(candidate)),
+    }), /advance the signed sequence/);
+  }
+});
+
+test("candidate accepts exact already-signed bytes and still rejects signature tampering", () => {
+  const bytes = Buffer.from(envelope.bytes, "base64");
+  const previous = JSON.parse(bytes);
+  validateCatalog(previous, envelope, { candidate: true, catalogBytes: bytes });
+  const invalid = structuredClone(envelope);
+  invalid.signatures.signatures[0].signature = Buffer.alloc(64).toString("base64");
+  assert.throws(() => validateCatalog(catalog, invalid, {
+    candidate: true, catalogBytes: Buffer.from(JSON.stringify(catalog)),
+  }), /signature does not verify/);
+});