diff --git a/graph-persistence.js b/graph-persistence.js
index eb676c2..1984671 100644
--- a/graph-persistence.js
+++ b/graph-persistence.js
@@ -21,6 +21,7 @@ export const GRAPH_LOAD_STATES = Object.freeze({
 });
 export const GRAPH_LOAD_PENDING_CHAT_ID = "__pending_chat__";
 export const GRAPH_SHADOW_SNAPSHOT_STORAGE_PREFIX = `${MODULE_NAME}:graph-shadow:`;
+export const GRAPH_IDENTITY_ALIAS_STORAGE_KEY = `${MODULE_NAME}:chat-identity-aliases`;
 export const GRAPH_STARTUP_RECONCILE_DELAYS_MS = [150, 600, 1800, 4000];
 
 // ═══════════════════════════════════════════════════════════
@@ -51,6 +52,247 @@ export function createLocalIntegritySlug() {
 
 export const GRAPH_PERSISTENCE_SESSION_ID = createLocalIntegritySlug();
 
+function normalizeIdentityValue(value) {
+  return String(value ?? "").trim();
+}
+
+function getLocalStorageSafe() {
+  const storage = globalThis.localStorage;
+  if (
+    !storage ||
+    typeof storage.getItem !== "function" ||
+    typeof storage.setItem !== "function"
+  ) {
+    return null;
+  }
+  return storage;
+}
+
+function getSessionStorageSafe() {
+  const storage = globalThis.sessionStorage;
+  if (!storage || typeof storage.getItem !== "function") {
+    return null;
+  }
+  return storage;
+}
+
+function listStorageKeys(storage) {
+  if (!storage) return [];
+
+  if (typeof storage.length === "number" && typeof storage.key === "function") {
+    const keys = [];
+    for (let index = 0; index < storage.length; index += 1) {
+      const key = storage.key(index);
+      if (typeof key === "string" && key) {
+        keys.push(key);
+      }
+    }
+    return keys;
+  }
+
+  if (storage.__store instanceof Map) {
+    return Array.from(storage.__store.keys()).map((key) => String(key));
+  }
+
+  return [];
+}
+
+function readGraphIdentityAliasRegistryRaw() {
+  const storage = getLocalStorageSafe();
+  if (!storage) {
+    return {
+      byIntegrity: {},
+    };
+  }
+
+  try {
+    const raw = storage.getItem(GRAPH_IDENTITY_ALIAS_STORAGE_KEY);
+    if (!raw) {
+      return {
+        byIntegrity: {},
+      };
+    }
+
+    const parsed = JSON.parse(raw);
+    const byIntegrity =
+      parsed?.byIntegrity &&
+      typeof parsed.byIntegrity === "object" &&
+      !Array.isArray(parsed.byIntegrity)
+        ? parsed.byIntegrity
+        : {};
+
+    return {
+      byIntegrity,
+    };
+  } catch {
+    return {
+      byIntegrity: {},
+    };
+  }
+}
+
+function writeGraphIdentityAliasRegistryRaw(registry = null) {
+  const storage = getLocalStorageSafe();
+  if (!storage) return false;
+
+  try {
+    storage.setItem(
+      GRAPH_IDENTITY_ALIAS_STORAGE_KEY,
+      JSON.stringify({
+        byIntegrity:
+          registry?.byIntegrity &&
+          typeof registry.byIntegrity === "object" &&
+          !Array.isArray(registry.byIntegrity)
+            ? registry.byIntegrity
+            : {},
+      }),
+    );
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function normalizeGraphIdentityAliasEntry(entry = {}, integrity = "") {
+  const normalizedIntegrity = normalizeIdentityValue(integrity || entry.integrity);
+  const normalizedPersistenceChatId = normalizeIdentityValue(
+    entry.persistenceChatId || normalizedIntegrity,
+  );
+  const normalizedHostChatIds = Array.from(
+    new Set(
+      (Array.isArray(entry.hostChatIds) ? entry.hostChatIds : [])
+        .map((value) => normalizeIdentityValue(value))
+        .filter(Boolean),
+    ),
+  ).slice(-16);
+
+  return {
+    integrity: normalizedIntegrity,
+    persistenceChatId: normalizedPersistenceChatId || normalizedIntegrity,
+    hostChatIds: normalizedHostChatIds,
+    updatedAt: String(entry.updatedAt || ""),
+  };
+}
+
+export function rememberGraphIdentityAlias({
+  integrity = "",
+  hostChatId = "",
+  persistenceChatId = "",
+} = {}) {
+  const normalizedIntegrity = normalizeIdentityValue(integrity);
+  if (!normalizedIntegrity) return null;
+
+  const normalizedHostChatId = normalizeIdentityValue(hostChatId);
+  const normalizedPersistenceChatId = normalizeIdentityValue(
+    persistenceChatId || normalizedIntegrity,
+  );
+  const registry = readGraphIdentityAliasRegistryRaw();
+  const existingEntry = normalizeGraphIdentityAliasEntry(
+    registry.byIntegrity?.[normalizedIntegrity] || {},
+    normalizedIntegrity,
+  );
+  const hostChatIds = Array.from(
+    new Set(
+      [normalizedHostChatId, ...existingEntry.hostChatIds].filter(Boolean),
+    ),
+  ).slice(-16);
+  const nextEntry = {
+    integrity: normalizedIntegrity,
+    persistenceChatId: normalizedPersistenceChatId || normalizedIntegrity,
+    hostChatIds,
+    updatedAt: new Date().toISOString(),
+  };
+
+  registry.byIntegrity[normalizedIntegrity] = nextEntry;
+  writeGraphIdentityAliasRegistryRaw(registry);
+  return nextEntry;
+}
+
+export function resolveGraphIdentityAliasByHostChatId(hostChatId = "") {
+  const normalizedHostChatId = normalizeIdentityValue(hostChatId);
+  if (!normalizedHostChatId) return "";
+
+  const registry = readGraphIdentityAliasRegistryRaw();
+  let bestEntry = null;
+
+  for (const [integrity, value] of Object.entries(registry.byIntegrity || {})) {
+    const entry = normalizeGraphIdentityAliasEntry(value, integrity);
+    if (!entry.hostChatIds.includes(normalizedHostChatId)) {
+      continue;
+    }
+
+    if (!bestEntry) {
+      bestEntry = entry;
+      continue;
+    }
+
+    if (String(entry.updatedAt || "") > String(bestEntry.updatedAt || "")) {
+      bestEntry = entry;
+    }
+  }
+
+  return normalizeIdentityValue(bestEntry?.persistenceChatId || "");
+}
+
+export function getGraphIdentityAliasCandidates({
+  integrity = "",
+  hostChatId = "",
+  persistenceChatId = "",
+} = {}) {
+  const normalizedIntegrity = normalizeIdentityValue(integrity);
+  const normalizedHostChatId = normalizeIdentityValue(hostChatId);
+  const normalizedPersistenceChatId = normalizeIdentityValue(persistenceChatId);
+  const registry = readGraphIdentityAliasRegistryRaw();
+  const candidates = [];
+  const seen = new Set();
+  const pushCandidate = (value) => {
+    const normalized = normalizeIdentityValue(value);
+    if (!normalized || seen.has(normalized)) return;
+    seen.add(normalized);
+    candidates.push(normalized);
+  };
+
+  if (normalizedIntegrity) {
+    const entry = normalizeGraphIdentityAliasEntry(
+      registry.byIntegrity?.[normalizedIntegrity] || {},
+      normalizedIntegrity,
+    );
+    pushCandidate(entry.persistenceChatId);
+    for (const value of entry.hostChatIds) {
+      pushCandidate(value);
+    }
+  } else if (normalizedHostChatId) {
+    pushCandidate(resolveGraphIdentityAliasByHostChatId(normalizedHostChatId));
+  }
+
+  pushCandidate(normalizedHostChatId);
+  pushCandidate(normalizedPersistenceChatId);
+  return candidates;
+}
+
+function normalizeShadowSnapshotPayload(snapshot = null) {
+  if (!snapshot || typeof snapshot !== "object") {
+    return null;
+  }
+
+  const serializedGraph = String(snapshot.serializedGraph || "");
+  const chatId = normalizeIdentityValue(snapshot.chatId);
+  if (!chatId || !serializedGraph) {
+    return null;
+  }
+
+  return {
+    chatId,
+    revision: Number.isFinite(snapshot.revision) ? snapshot.revision : 0,
+    serializedGraph,
+    updatedAt: String(snapshot.updatedAt || ""),
+    reason: String(snapshot.reason || ""),
+    integrity: normalizeIdentityValue(snapshot.integrity),
+    persistedChatId: normalizeIdentityValue(snapshot.persistedChatId),
+    debugReason: String(snapshot.debugReason || snapshot.reason || ""),
+  };
+}
+
 // ═══════════════════════════════════════════════════════════
 // 图谱持久化元数据
 // ═══════════════════════════════════════════════════════════
@@ -146,33 +388,72 @@ export function readGraphShadowSnapshot(chatId = "") {
   if (!storageKey) return null;
 
   try {
-    const raw = globalThis.sessionStorage?.getItem(storageKey);
+    const raw = getSessionStorageSafe()?.getItem(storageKey);
     if (!raw) return null;
-    const snapshot = JSON.parse(raw);
-    if (
-      !snapshot ||
-      typeof snapshot !== "object" ||
-      String(snapshot.chatId || "") !== String(chatId || "") ||
-      typeof snapshot.serializedGraph !== "string" ||
-      !snapshot.serializedGraph
-    ) {
+    const snapshot = normalizeShadowSnapshotPayload(JSON.parse(raw));
+    if (!snapshot || snapshot.chatId !== String(chatId || "")) {
       return null;
     }
-    return {
-      chatId: String(snapshot.chatId || ""),
-      revision: Number.isFinite(snapshot.revision) ? snapshot.revision : 0,
-      serializedGraph: snapshot.serializedGraph,
-      updatedAt: String(snapshot.updatedAt || ""),
-      reason: String(snapshot.reason || ""),
-      integrity: String(snapshot.integrity || ""),
-      persistedChatId: String(snapshot.persistedChatId || ""),
-      debugReason: String(snapshot.debugReason || snapshot.reason || ""),
-    };
+    return snapshot;
   } catch {
     return null;
   }
 }
 
+export function findGraphShadowSnapshotByIntegrity(
+  integrity = "",
+  { excludeChatIds = [] } = {},
+) {
+  const normalizedIntegrity = normalizeIdentityValue(integrity);
+  if (!normalizedIntegrity) return null;
+
+  const storage = getSessionStorageSafe();
+  if (!storage) return null;
+
+  const excludedChatIds = new Set(
+    (Array.isArray(excludeChatIds) ? excludeChatIds : [])
+      .map((value) => normalizeIdentityValue(value))
+      .filter(Boolean),
+  );
+
+  let bestSnapshot = null;
+  for (const key of listStorageKeys(storage)) {
+    if (!String(key || "").startsWith(GRAPH_SHADOW_SNAPSHOT_STORAGE_PREFIX)) {
+      continue;
+    }
+
+    try {
+      const snapshot = normalizeShadowSnapshotPayload(
+        JSON.parse(storage.getItem(key)),
+      );
+      if (!snapshot || snapshot.integrity !== normalizedIntegrity) {
+        continue;
+      }
+      if (excludedChatIds.has(snapshot.chatId)) {
+        continue;
+      }
+
+      const bestRevision = Number(bestSnapshot?.revision || 0);
+      const nextRevision = Number(snapshot.revision || 0);
+      if (!bestSnapshot || nextRevision > bestRevision) {
+        bestSnapshot = snapshot;
+        continue;
+      }
+
+      if (
+        nextRevision === bestRevision &&
+        String(snapshot.updatedAt || "") > String(bestSnapshot.updatedAt || "")
+      ) {
+        bestSnapshot = snapshot;
+      }
+    } catch {
+      // ignore broken shadow snapshot payloads
+    }
+  }
+
+  return bestSnapshot;
+}
+
 /**
  * @param {string} chatId
  * @param {object} graph
@@ -191,7 +472,7 @@ export function writeGraphShadowSnapshot(
   try {
     const serializedGraph = serializeGraph(graph);
     const persistedMeta = getGraphPersistenceMeta(graph) || {};
-    globalThis.sessionStorage?.setItem(
+    getSessionStorageSafe()?.setItem(
       storageKey,
       JSON.stringify({
         chatId: String(chatId || ""),
@@ -216,7 +497,7 @@ export function removeGraphShadowSnapshot(chatId = "") {
   if (!storageKey) return false;
 
   try {
-    globalThis.sessionStorage?.removeItem(storageKey);
+    getSessionStorageSafe()?.removeItem(storageKey);
     return true;
   } catch {
     return false;
diff --git a/index.js b/index.js
index 7b00c7f..6681156 100644
--- a/index.js
+++ b/index.js
@@ -18,6 +18,8 @@ import {
 
 import { BmeChatManager } from "./bme-chat-manager.js";
 import {
+  BmeDatabase,
+  buildBmeDbName,
   buildGraphFromSnapshot,
   buildSnapshotFromGraph,
   ensureDexieLoaded,
@@ -82,6 +84,7 @@ import {
   generateSynopsis,
 } from "./extractor.js";
 import {
+  findGraphShadowSnapshotByIntegrity,
   GRAPH_LOAD_PENDING_CHAT_ID,
   GRAPH_LOAD_STATES,
   GRAPH_METADATA_KEY,
@@ -90,7 +93,12 @@ import {
   cloneGraphForPersistence,
   cloneRuntimeDebugValue,
   getGraphPersistedRevision,
+  getGraphPersistenceMeta,
+  getGraphIdentityAliasCandidates,
+  readGraphShadowSnapshot,
   removeGraphShadowSnapshot,
+  rememberGraphIdentityAlias,
+  resolveGraphIdentityAliasByHostChatId,
   stampGraphPersistenceMeta,
   writeChatMetadataPatch,
   writeGraphShadowSnapshot,
@@ -930,10 +938,19 @@ function throwIfAborted(signal, message = "操作已终止") {
 
 function assertRecoveryChatStillActive(expectedChatId, label = "") {
   if (!expectedChatId) return;
-  const currentId = getCurrentChatId();
-  if (currentId && currentId !== expectedChatId) {
+  const currentIdentity = resolveCurrentChatIdentity(getContext());
+  const currentId = normalizeChatIdCandidate(currentIdentity.chatId);
+  const normalizedExpectedChatId = normalizeChatIdCandidate(expectedChatId);
+  if (
+    currentId &&
+    normalizedExpectedChatId &&
+    !doesChatIdMatchResolvedGraphIdentity(
+      normalizedExpectedChatId,
+      currentIdentity,
+    )
+  ) {
     throw createAbortError(
-      `历史恢复已终止：聊天已从 ${expectedChatId} 切换到 ${currentId}${label ? ` (${label})` : ""}`,
+      `历史恢复已终止：聊天已从 ${normalizedExpectedChatId} 切换到 ${currentId}${label ? ` (${label})` : ""}`,
     );
   }
 }
@@ -3309,7 +3326,7 @@ function isHostChatMetadataReady(context = getContext()) {
   return false;
 }
 
-function resolveCurrentChatIdentity(context = getContext()) {
+function resolveCurrentHostChatId(context = getContext()) {
   const candidates = [
     context?.chatId,
     context?.getCurrentChatId?.(),
@@ -3320,13 +3337,43 @@ function resolveCurrentChatIdentity(context = getContext()) {
     context?.chatMetadata?.sessionId,
   ];
 
-  const chatId =
+  return (
     candidates
       .map((candidate) => normalizeChatIdCandidate(candidate))
-      .find(Boolean) || "";
+      .find(Boolean) || ""
+  );
+}
+
+function resolveCurrentChatIdentity(context = getContext()) {
+  const hostChatId = resolveCurrentHostChatId(context);
+  const integrity =
+    typeof getChatMetadataIntegrity === "function"
+      ? getChatMetadataIntegrity(context)
+      : normalizeChatIdCandidate(
+          context?.chatMetadata?.integrity ||
+            context?.chatMetadata?.chat_id ||
+            context?.chatMetadata?.chatId ||
+            "",
+        );
+  const aliasedChatId =
+    !integrity &&
+    hostChatId &&
+    typeof resolveGraphIdentityAliasByHostChatId === "function"
+      ? resolveGraphIdentityAliasByHostChatId(hostChatId)
+      : "";
+  const chatId = integrity || aliasedChatId || hostChatId;
 
   return {
     chatId,
+    hostChatId,
+    integrity,
+    identitySource: integrity
+      ? "integrity"
+      : aliasedChatId
+        ? "alias"
+        : hostChatId
+          ? "host-chat-id"
+          : "",
     hasLikelySelectedChat: hasLikelySelectedChatContext(context),
   };
 }
@@ -3335,6 +3382,250 @@ function getCurrentChatId(context = getContext()) {
   return resolveCurrentChatIdentity(context).chatId;
 }
 
+function rememberResolvedGraphIdentityAlias(
+  context = getContext(),
+  persistenceChatId = getCurrentChatId(context),
+) {
+  const identity = resolveCurrentChatIdentity(context);
+  if (!identity.integrity || !persistenceChatId) {
+    return null;
+  }
+
+  return rememberGraphIdentityAlias({
+    integrity: identity.integrity,
+    hostChatId: identity.hostChatId,
+    persistenceChatId,
+  });
+}
+
+function buildLegacyGraphIdentityCandidates(
+  targetChatId,
+  context = getContext(),
+  { shadowSnapshot = null } = {},
+) {
+  const normalizedTargetChatId = normalizeChatIdCandidate(targetChatId);
+  const identity = resolveCurrentChatIdentity(context);
+  const candidates = new Set();
+  const addCandidate = (value) => {
+    const normalized = normalizeChatIdCandidate(value);
+    if (!normalized || normalized === normalizedTargetChatId) return;
+    candidates.add(normalized);
+  };
+
+  addCandidate(identity.hostChatId);
+  for (const aliasCandidate of getGraphIdentityAliasCandidates({
+    integrity: identity.integrity,
+    hostChatId: identity.hostChatId,
+    persistenceChatId: normalizedTargetChatId,
+  })) {
+    addCandidate(aliasCandidate);
+  }
+
+  const currentGraphMeta = getGraphPersistenceMeta(currentGraph) || {};
+  const runtimeGraphIntegrity = normalizeChatIdCandidate(
+    currentGraphMeta.integrity || graphPersistenceState.metadataIntegrity,
+  );
+  if (
+    identity.integrity &&
+    runtimeGraphIntegrity &&
+    runtimeGraphIntegrity === identity.integrity
+  ) {
+    addCandidate(graphPersistenceState.chatId);
+    addCandidate(currentGraph?.historyState?.chatId);
+    addCandidate(currentGraphMeta.chatId);
+  }
+
+  addCandidate(shadowSnapshot?.chatId);
+  addCandidate(shadowSnapshot?.persistedChatId);
+  return Array.from(candidates);
+}
+
+async function doesIndexedDbChatStoreExist(chatId = "") {
+  const normalizedChatId = normalizeChatIdCandidate(chatId);
+  if (!normalizedChatId) return false;
+
+  const DexieCtor = globalThis.Dexie || (await ensureDexieLoaded());
+  if (typeof DexieCtor?.exists === "function") {
+    return await DexieCtor.exists(buildBmeDbName(normalizedChatId));
+  }
+
+  if (typeof DexieCtor?.getDatabaseNames === "function") {
+    const names = await DexieCtor.getDatabaseNames();
+    return Array.isArray(names)
+      ? names.includes(buildBmeDbName(normalizedChatId))
+      : false;
+  }
+
+  return false;
+}
+
+async function exportIndexedDbSnapshotForChat(chatId = "") {
+  const normalizedChatId = normalizeChatIdCandidate(chatId);
+  if (!normalizedChatId) {
+    return null;
+  }
+
+  if (!(await doesIndexedDbChatStoreExist(normalizedChatId))) {
+    return null;
+  }
+
+  const DexieCtor = globalThis.Dexie || (await ensureDexieLoaded());
+  const db = new BmeDatabase(normalizedChatId, {
+    dexieClass: DexieCtor,
+  });
+
+  try {
+    await db.open();
+    return await db.exportSnapshot();
+  } finally {
+    await db.close();
+  }
+}
+
+function buildRecoveredSnapshotForChatIdentity(
+  graph,
+  targetChatId,
+  {
+    revision = 0,
+    integrity = "",
+    source = "identity-recovery",
+    legacyChatId = "",
+  } = {},
+) {
+  const normalizedTargetChatId = normalizeChatIdCandidate(targetChatId);
+  const normalizedIntegrity = normalizeChatIdCandidate(integrity);
+  const normalizedLegacyChatId = normalizeChatIdCandidate(legacyChatId);
+  const normalizedGraph = cloneGraphForPersistence(graph, normalizedTargetChatId);
+  const effectiveRevision = Math.max(
+    1,
+    normalizeIndexedDbRevision(
+      revision || graphPersistenceState.revision || getGraphPersistedRevision(graph),
+    ),
+  );
+
+  stampGraphPersistenceMeta(normalizedGraph, {
+    revision: effectiveRevision,
+    reason: source,
+    chatId: normalizedTargetChatId,
+    integrity: normalizedIntegrity,
+  });
+
+  return buildSnapshotFromGraph(normalizedGraph, {
+    chatId: normalizedTargetChatId,
+    revision: effectiveRevision,
+    lastModified: Date.now(),
+    meta: {
+      storagePrimary: "indexeddb",
+      lastMutationReason: String(source || "identity-recovery"),
+      integrity: normalizedIntegrity,
+      migratedFromChatId: normalizedLegacyChatId,
+      identityMigrationSource: String(source || "identity-recovery"),
+    },
+  });
+}
+
+async function importRecoveredSnapshotToIndexedDb(
+  targetDb,
+  targetChatId,
+  graph,
+  { revision = 0, integrity = "", source = "identity-recovery", legacyChatId = "" } = {},
+) {
+  const snapshot = buildRecoveredSnapshotForChatIdentity(graph, targetChatId, {
+    revision,
+    integrity,
+    source,
+    legacyChatId,
+  });
+  const importResult = await targetDb.importSnapshot(snapshot, {
+    mode: "replace",
+    preserveRevision: true,
+    revision: snapshot.meta.revision,
+    markSyncDirty: true,
+  });
+  snapshot.meta.revision = normalizeIndexedDbRevision(
+    importResult?.revision,
+    snapshot.meta.revision,
+  );
+  return snapshot;
+}
+
+function doesChatIdMatchResolvedGraphIdentity(
+  candidateChatId,
+  identity = resolveCurrentChatIdentity(getContext()),
+) {
+  const normalizedCandidate = normalizeChatIdCandidate(candidateChatId);
+  if (!normalizedCandidate || !identity || typeof identity !== "object") {
+    return false;
+  }
+
+  const knownChatIds = new Set();
+  const addKnownChatId = (value) => {
+    const normalized = normalizeChatIdCandidate(value);
+    if (normalized) {
+      knownChatIds.add(normalized);
+    }
+  };
+
+  addKnownChatId(identity.chatId);
+  addKnownChatId(identity.hostChatId);
+  addKnownChatId(identity.integrity);
+
+  for (const aliasCandidate of getGraphIdentityAliasCandidates({
+    integrity: identity.integrity,
+    hostChatId: identity.hostChatId,
+    persistenceChatId: identity.chatId,
+  })) {
+    addKnownChatId(aliasCandidate);
+  }
+
+  return knownChatIds.has(normalizedCandidate);
+}
+
+function resolveCompatibleGraphShadowSnapshot(
+  identity = resolveCurrentChatIdentity(getContext()),
+) {
+  if (!identity || typeof identity !== "object") {
+    return null;
+  }
+
+  const directSnapshot = readGraphShadowSnapshot(identity.chatId);
+  if (directSnapshot) {
+    return directSnapshot;
+  }
+
+  const seenChatIds = new Set(
+    [identity.chatId].map((value) => normalizeChatIdCandidate(value)).filter(Boolean),
+  );
+  const readByChatId = (value) => {
+    const normalized = normalizeChatIdCandidate(value);
+    if (!normalized || seenChatIds.has(normalized)) {
+      return null;
+    }
+    seenChatIds.add(normalized);
+    return readGraphShadowSnapshot(normalized);
+  };
+
+  const hostSnapshot = readByChatId(identity.hostChatId);
+  if (hostSnapshot) {
+    return hostSnapshot;
+  }
+
+  for (const aliasCandidate of getGraphIdentityAliasCandidates({
+    integrity: identity.integrity,
+    hostChatId: identity.hostChatId,
+    persistenceChatId: identity.chatId,
+  })) {
+    const aliasSnapshot = readByChatId(aliasCandidate);
+    if (aliasSnapshot) {
+      return aliasSnapshot;
+    }
+  }
+
+  return findGraphShadowSnapshotByIntegrity(identity.integrity, {
+    excludeChatIds: Array.from(seenChatIds),
+  });
+}
+
 async function refreshRuntimeGraphAfterSyncApplied(syncPayload = {}) {
   const action = String(syncPayload?.action || "")
     .trim()
@@ -3348,8 +3639,14 @@ async function refreshRuntimeGraphAfterSyncApplied(syncPayload = {}) {
   }
 
   const syncedChatId = normalizeChatIdCandidate(syncPayload?.chatId);
-  const activeChatId = normalizeChatIdCandidate(getCurrentChatId());
-  const targetChatId = syncedChatId || activeChatId;
+  const activeIdentity = resolveCurrentChatIdentity(getContext());
+  const activeChatId = normalizeChatIdCandidate(activeIdentity.chatId);
+  const targetChatId =
+    activeChatId &&
+    syncedChatId &&
+    doesChatIdMatchResolvedGraphIdentity(syncedChatId, activeIdentity)
+      ? activeChatId
+      : syncedChatId || activeChatId;
 
   if (!targetChatId) {
     return {
@@ -3671,6 +3968,223 @@ function readLegacyGraphFromChatMetadata(chatId, context = getContext()) {
   }
 }
 
+async function maybeRecoverIndexedDbGraphFromStableIdentity(
+  chatId,
+  context = getContext(),
+  { source = "unknown", db = null } = {},
+) {
+  const normalizedChatId = normalizeChatIdCandidate(chatId);
+  if (!normalizedChatId) {
+    return {
+      migrated: false,
+      reason: "identity-recovery-missing-chat-id",
+      chatId: "",
+    };
+  }
+
+  const identity = resolveCurrentChatIdentity(context);
+  if (!identity.integrity) {
+    return {
+      migrated: false,
+      reason: "identity-recovery-integrity-missing",
+      chatId: normalizedChatId,
+    };
+  }
+
+  const manager = ensureBmeChatManager();
+  if (!manager) {
+    return {
+      migrated: false,
+      reason: "identity-recovery-manager-unavailable",
+      chatId: normalizedChatId,
+    };
+  }
+
+  const targetDb = db || (await manager.getCurrentDb(normalizedChatId));
+  if (!targetDb) {
+    return {
+      migrated: false,
+      reason: "identity-recovery-db-unavailable",
+      chatId: normalizedChatId,
+    };
+  }
+
+  const emptyStatus = await targetDb.isEmpty();
+  if (!emptyStatus?.empty) {
+    return {
+      migrated: false,
+      reason: "identity-recovery-target-not-empty",
+      chatId: normalizedChatId,
+      emptyStatus,
+    };
+  }
+
+  const finalizeMigration = async (
+    graph,
+    {
+      revision = 0,
+      legacyChatId = "",
+      migrationSource = "identity-recovery",
+      shadowChatId = "",
+    } = {},
+  ) => {
+    const snapshot = await importRecoveredSnapshotToIndexedDb(
+      targetDb,
+      normalizedChatId,
+      graph,
+      {
+        revision,
+        integrity: identity.integrity,
+        source: migrationSource,
+        legacyChatId,
+      },
+    );
+    cacheIndexedDbSnapshot(normalizedChatId, snapshot);
+    rememberResolvedGraphIdentityAlias(context, normalizedChatId);
+
+    if (shadowChatId && shadowChatId !== normalizedChatId) {
+      removeGraphShadowSnapshot(shadowChatId);
+    }
+
+    let syncResult = {
+      synced: false,
+      reason: "identity-recovery-sync-skipped",
+      chatId: normalizedChatId,
+    };
+    try {
+      syncResult = await syncNow(
+        normalizedChatId,
+        buildBmeSyncRuntimeOptions({
+          reason: "identity-recovery",
+          trigger: `${String(source || "identity-recovery")}:identity-recovery`,
+        }),
+      );
+    } catch (syncError) {
+      console.warn("[ST-BME] 身份恢复后的同步失败:", syncError);
+      syncResult = {
+        synced: false,
+        reason: "identity-recovery-sync-failed",
+        chatId: normalizedChatId,
+        error: syncError?.message || String(syncError),
+      };
+    }
+
+    return {
+      migrated: true,
+      reason: "identity-recovery-completed",
+      chatId: normalizedChatId,
+      legacyChatId: normalizeChatIdCandidate(legacyChatId),
+      source: migrationSource,
+      snapshot,
+      syncResult,
+    };
+  };
+
+  const currentGraphMeta = getGraphPersistenceMeta(currentGraph) || {};
+  const runtimeGraphIntegrity = normalizeChatIdCandidate(
+    currentGraphMeta.integrity || graphPersistenceState.metadataIntegrity,
+  );
+  const runtimeGraphChatId = normalizeChatIdCandidate(
+    currentGraph?.historyState?.chatId ||
+      currentGraphMeta.chatId ||
+      graphPersistenceState.chatId,
+  );
+
+  if (
+    currentGraph &&
+    !isGraphEffectivelyEmpty(currentGraph) &&
+    runtimeGraphIntegrity &&
+    runtimeGraphIntegrity === identity.integrity &&
+    runtimeGraphChatId &&
+    runtimeGraphChatId !== normalizedChatId
+  ) {
+    return await finalizeMigration(currentGraph, {
+      revision: Math.max(
+        graphPersistenceState.revision || 0,
+        getGraphPersistedRevision(currentGraph),
+        1,
+      ),
+      legacyChatId: runtimeGraphChatId,
+      migrationSource: "runtime-identity-promotion",
+    });
+  }
+
+  const aliasShadowSnapshot = findGraphShadowSnapshotByIntegrity(
+    identity.integrity,
+    {
+      excludeChatIds: [normalizedChatId],
+    },
+  );
+  if (aliasShadowSnapshot?.serializedGraph) {
+    try {
+      const shadowGraph = normalizeGraphRuntimeState(
+        deserializeGraph(aliasShadowSnapshot.serializedGraph),
+        normalizedChatId,
+      );
+      if (!isGraphEffectivelyEmpty(shadowGraph)) {
+        return await finalizeMigration(shadowGraph, {
+          revision: Math.max(
+            Number(aliasShadowSnapshot.revision || 0),
+            getGraphPersistedRevision(shadowGraph),
+            1,
+          ),
+          legacyChatId:
+            aliasShadowSnapshot.persistedChatId || aliasShadowSnapshot.chatId,
+          migrationSource: "shadow-identity-recovery",
+          shadowChatId: aliasShadowSnapshot.chatId,
+        });
+      }
+    } catch (error) {
+      console.warn("[ST-BME] 通过影子快照恢复聊天身份失败:", error);
+    }
+  }
+
+  const legacyCandidates = buildLegacyGraphIdentityCandidates(
+    normalizedChatId,
+    context,
+    {
+      shadowSnapshot: aliasShadowSnapshot,
+    },
+  );
+
+  for (const legacyChatId of legacyCandidates) {
+    try {
+      const legacySnapshot = await exportIndexedDbSnapshotForChat(legacyChatId);
+      if (!isIndexedDbSnapshotMeaningful(legacySnapshot)) {
+        continue;
+      }
+
+      const legacyGraph = buildGraphFromSnapshot(legacySnapshot, {
+        chatId: legacyChatId,
+      });
+      if (isGraphEffectivelyEmpty(legacyGraph)) {
+        continue;
+      }
+
+      return await finalizeMigration(legacyGraph, {
+        revision: Math.max(
+          normalizeIndexedDbRevision(legacySnapshot?.meta?.revision),
+          getGraphPersistedRevision(legacyGraph),
+          1,
+        ),
+        legacyChatId,
+        migrationSource: "indexeddb-identity-alias",
+      });
+    } catch (error) {
+      console.warn("[ST-BME] 读取旧身份 IndexedDB 图谱失败:", {
+        legacyChatId,
+        error,
+      });
+    }
+  }
+
+  return {
+    migrated: false,
+    reason: "identity-recovery-no-match",
+    chatId: normalizedChatId,
+  };
+}
+
 async function maybeMigrateLegacyGraphToIndexedDb(
   chatId,
   context = getContext(),
@@ -3980,6 +4494,14 @@ function applyIndexedDbSnapshotToRuntime(
     normalizeGraphRuntimeState(graphFromSnapshot, normalizedChatId),
     normalizedChatId,
   );
+  stampGraphPersistenceMeta(currentGraph, {
+    revision,
+    reason: `indexeddb:${String(source || "indexeddb")}`,
+    chatId: normalizedChatId,
+    integrity:
+      normalizeChatIdCandidate(snapshot?.meta?.integrity) ||
+      getChatMetadataIntegrity(getContext()),
+  });
   currentGraph.vectorIndexState.lastIntegrityIssue = null;
 
   extractionCount = Number.isFinite(currentGraph?.historyState?.extractionCount)
@@ -4045,6 +4567,7 @@ function applyIndexedDbSnapshotToRuntime(
       at: Date.now(),
     },
   });
+  rememberResolvedGraphIdentityAlias(getContext(), normalizedChatId);
 
   removeGraphShadowSnapshot(normalizedChatId);
   refreshPanelLiveState();
@@ -4101,14 +4624,59 @@ async function loadGraphFromIndexedDb(
     }
     const db = await manager.getCurrentDb(normalizedChatId);
 
-    const migrationResult = await maybeMigrateLegacyGraphToIndexedDb(
-      normalizedChatId,
-      getContext(),
-      {
-        source,
-        db,
-      },
-    );
+    const identityRecoveryResult =
+      await maybeRecoverIndexedDbGraphFromStableIdentity(
+        normalizedChatId,
+        getContext(),
+        {
+          source,
+          db,
+        },
+      );
+
+    if (identityRecoveryResult?.migrated) {
+      const recoveredRevision = normalizeIndexedDbRevision(
+        identityRecoveryResult?.snapshot?.meta?.revision,
+      );
+      updateGraphPersistenceState({
+        storagePrimary: "indexeddb",
+        storageMode: "indexeddb",
+        indexedDbRevision: recoveredRevision,
+        indexedDbLastError: "",
+        lastSyncError: "",
+        dualWriteLastResult: {
+          action: "identity-recovery",
+          source: String(identityRecoveryResult?.source || "indexeddb"),
+          success: true,
+          chatId: normalizedChatId,
+          legacyChatId: String(identityRecoveryResult?.legacyChatId || ""),
+          revision: recoveredRevision,
+          reason: String(
+            identityRecoveryResult?.reason || "identity-recovery",
+          ),
+          at: Date.now(),
+          syncResult: cloneRuntimeDebugValue(
+            identityRecoveryResult?.syncResult,
+            null,
+          ),
+        },
+      });
+    }
+
+    const migrationResult = identityRecoveryResult?.migrated
+      ? {
+          migrated: false,
+          reason: "identity-recovery-already-applied",
+          chatId: normalizedChatId,
+        }
+      : await maybeMigrateLegacyGraphToIndexedDb(
+          normalizedChatId,
+          getContext(),
+          {
+            source,
+            db,
+          },
+        );
 
     if (migrationResult?.migrated) {
       const migratedRevision = normalizeIndexedDbRevision(
@@ -4146,8 +4714,11 @@ async function loadGraphFromIndexedDb(
         },
       });
     }
+    const snapshot =
+      identityRecoveryResult?.snapshot ||
+      migrationResult?.snapshot ||
+      (await db.exportSnapshot());
 
-    const snapshot = migrationResult?.snapshot || (await db.exportSnapshot());
     cacheIndexedDbSnapshot(normalizedChatId, snapshot);
 
     if (!isIndexedDbSnapshotMeaningful(snapshot)) {
@@ -4713,6 +5284,7 @@ function persistGraphToChatMetadata(
     queuedPersistRotateIntegrity: false,
     queuedPersistReason: "",
   });
+  rememberResolvedGraphIdentityAlias(context, chatId);
 
   return buildGraphPersistResult({
     saved: true,
@@ -5949,7 +6521,7 @@ function loadGraphFromChat(options = {}) {
         normalizeGraphRuntimeState(deserializeGraph(savedData), chatId),
         chatId,
       );
-      const shadowSnapshot = readGraphShadowSnapshot(chatId);
+      const shadowSnapshot = resolveCompatibleGraphShadowSnapshot(chatIdentity);
       const shadowDecision = shouldPreferShadowSnapshotOverOfficial(
         officialGraph,
         shadowSnapshot,
@@ -5976,6 +6548,12 @@ function loadGraphFromChat(options = {}) {
 
       clearPendingGraphLoadRetry();
       currentGraph = officialGraph;
+      stampGraphPersistenceMeta(currentGraph, {
+        revision: officialRevision,
+        reason: `${source}:metadata-compat-provisional`,
+        chatId,
+        integrity: getChatMetadataIntegrity(context),
+      });
       extractionCount = Number.isFinite(
         currentGraph?.historyState?.extractionCount,
       )
@@ -6043,6 +6621,7 @@ function loadGraphFromChat(options = {}) {
           at: Date.now(),
         },
       });
+      rememberResolvedGraphIdentityAlias(context, chatId);
 
       scheduleIndexedDbGraphProbe(chatId, {
         source: `${source}:indexeddb-probe`,
@@ -6126,6 +6705,7 @@ async function saveGraphToIndexedDb(
       };
     }
     const db = await manager.getCurrentDb(normalizedChatId);
+    const currentIdentity = resolveCurrentChatIdentity(getContext());
     const baseSnapshot =
       readCachedIndexedDbSnapshot(normalizedChatId) ||
       (await db.exportSnapshot());
@@ -6137,6 +6717,9 @@ async function saveGraphToIndexedDb(
       meta: {
         storagePrimary: "indexeddb",
         lastMutationReason: String(reason || "graph-save"),
+        integrity:
+          currentIdentity.integrity || graphPersistenceState.metadataIntegrity,
+        hostChatId: currentIdentity.hostChatId || "",
       },
     });
     const importResult = await db.importSnapshot(snapshot, {
@@ -6179,6 +6762,7 @@ async function saveGraphToIndexedDb(
         at: Date.now(),
       },
     });
+    rememberResolvedGraphIdentityAlias(getContext(), normalizedChatId);
 
     return {
       saved: true,
diff --git a/tests/graph-persistence.mjs b/tests/graph-persistence.mjs
index 7e7b9ed..e106086 100644
--- a/tests/graph-persistence.mjs
+++ b/tests/graph-persistence.mjs
@@ -4,15 +4,22 @@ import path from "node:path";
 import { fileURLToPath } from "node:url";
 import vm from "node:vm";
 
-import { buildGraphFromSnapshot, buildSnapshotFromGraph } from "../bme-db.js";
+import {
+  buildBmeDbName,
+  buildGraphFromSnapshot,
+  buildSnapshotFromGraph,
+} from "../bme-db.js";
 import { onMessageReceivedController } from "../event-binding.js";
 import {
   cloneGraphForPersistence,
   cloneRuntimeDebugValue,
+  findGraphShadowSnapshotByIntegrity,
   getGraphPersistedRevision,
+  getGraphIdentityAliasCandidates,
   getGraphPersistenceMeta,
   getGraphShadowSnapshotStorageKey,
   GRAPH_LOAD_PENDING_CHAT_ID,
+  GRAPH_IDENTITY_ALIAS_STORAGE_KEY,
   GRAPH_LOAD_STATES,
   GRAPH_METADATA_KEY,
   GRAPH_PERSISTENCE_META_KEY,
@@ -21,7 +28,9 @@ import {
   GRAPH_STARTUP_RECONCILE_DELAYS_MS,
   MODULE_NAME,
   readGraphShadowSnapshot,
+  rememberGraphIdentityAlias,
   removeGraphShadowSnapshot,
+  resolveGraphIdentityAliasByHostChatId,
   shouldPreferShadowSnapshotOverOfficial,
   stampGraphPersistenceMeta,
   writeChatMetadataPatch,
@@ -83,6 +92,28 @@ const messageSnippet = extractSnippet(
 );
 
 function createSessionStorage(seed = null) {
+  const store = seed instanceof Map ? seed : new Map();
+  return {
+    __store: store,
+    get length() {
+      return store.size;
+    },
+    key(index) {
+      return Array.from(store.keys())[Number(index)] ?? null;
+    },
+    getItem(key) {
+      return store.has(key) ? store.get(key) : null;
+    },
+    setItem(key, value) {
+      store.set(String(key), String(value));
+    },
+    removeItem(key) {
+      store.delete(String(key));
+    },
+  };
+}
+
+function createLocalStorage(seed = null) {
   const store = seed instanceof Map ? seed : new Map();
   return {
     __store: store,
@@ -154,15 +185,75 @@ async function createGraphPersistenceHarness({
   chatId = "chat-test",
   chatMetadata = undefined,
   sessionStore = null,
+  localStore = null,
   globalChatId = "",
   characterId = "",
   groupId = null,
   indexedDbSnapshot = null,
+  indexedDbSnapshots = null,
   chat = [],
 } = {}) {
   const timers = new Map();
   let nextTimerId = 1;
   const storage = createSessionStorage(sessionStore);
+  const localStorage = createLocalStorage(localStore);
+  const indexedDbSnapshotMap =
+    indexedDbSnapshots instanceof Map
+      ? new Map(indexedDbSnapshots)
+      : new Map(
+          Object.entries(
+            indexedDbSnapshots &&
+              typeof indexedDbSnapshots === "object" &&
+              !Array.isArray(indexedDbSnapshots)
+              ? indexedDbSnapshots
+              : {},
+          ),
+        );
+
+  if (indexedDbSnapshot) {
+    const primaryChatId = String(chatId || globalChatId || "");
+    if (primaryChatId) {
+      indexedDbSnapshotMap.set(primaryChatId, structuredClone(indexedDbSnapshot));
+    }
+  }
+
+  function buildEmptyIndexedDbSnapshot(targetChatId = "") {
+    return {
+      meta: { revision: 0, chatId: String(targetChatId || "") },
+      nodes: [],
+      edges: [],
+      tombstones: [],
+      state: { lastProcessedFloor: -1, extractionCount: 0 },
+    };
+  }
+
+  function getIndexedDbSnapshotForChat(targetChatId = "") {
+    const normalizedChatId = String(targetChatId || "");
+    if (normalizedChatId && indexedDbSnapshotMap.has(normalizedChatId)) {
+      return structuredClone(indexedDbSnapshotMap.get(normalizedChatId));
+    }
+
+    if (
+      normalizedChatId &&
+      indexedDbSnapshot &&
+      !indexedDbSnapshotMap.size &&
+      normalizedChatId === String(chatId || globalChatId || "")
+    ) {
+      return structuredClone(indexedDbSnapshot);
+    }
+
+    return buildEmptyIndexedDbSnapshot(normalizedChatId);
+  }
+
+  function setIndexedDbSnapshotForChat(targetChatId = "", snapshot = null) {
+    const normalizedChatId = String(targetChatId || "");
+    if (!normalizedChatId) return;
+    if (!snapshot) {
+      indexedDbSnapshotMap.delete(normalizedChatId);
+      return;
+    }
+    indexedDbSnapshotMap.set(normalizedChatId, structuredClone(snapshot));
+  }
 
   const runtimeContext = {
     console,
@@ -176,8 +267,12 @@ async function createGraphPersistenceHarness({
     Boolean,
     structuredClone,
     result: null,
-    __indexedDbSnapshot: indexedDbSnapshot,
+    __indexedDbSnapshot: getIndexedDbSnapshotForChat(
+      String(chatId || globalChatId || ""),
+    ),
+    __indexedDbSnapshots: indexedDbSnapshotMap,
     sessionStorage: storage,
+    localStorage,
     setTimeout(fn, delay) {
       const id = nextTimerId++;
       timers.set(id, { fn, delay });
@@ -211,6 +306,21 @@ async function createGraphPersistenceHarness({
       },
     },
     __globalChatId: String(globalChatId || ""),
+    Dexie: {
+      async exists(dbName = "") {
+        return Array.from(indexedDbSnapshotMap.keys()).some(
+          (candidateChatId) => buildBmeDbName(candidateChatId) === String(dbName),
+        );
+      },
+      async getDatabaseNames() {
+        return Array.from(indexedDbSnapshotMap.keys()).map((candidateChatId) =>
+          buildBmeDbName(candidateChatId),
+        );
+      },
+    },
+    async ensureDexieLoaded() {
+      return runtimeContext.Dexie;
+    },
     refreshPanelLiveState() {
       runtimeContext.__panelRefreshCount += 1;
     },
@@ -241,7 +351,9 @@ async function createGraphPersistenceHarness({
     onMessageReceivedController,
     getGraphPersistenceMeta,
     getGraphPersistedRevision,
+    getGraphIdentityAliasCandidates,
     getGraphShadowSnapshotStorageKey,
+    GRAPH_IDENTITY_ALIAS_STORAGE_KEY,
     GRAPH_LOAD_PENDING_CHAT_ID,
     GRAPH_LOAD_STATES,
     GRAPH_METADATA_KEY,
@@ -250,14 +362,141 @@ async function createGraphPersistenceHarness({
     GRAPH_SHADOW_SNAPSHOT_STORAGE_PREFIX,
     GRAPH_STARTUP_RECONCILE_DELAYS_MS,
     MODULE_NAME,
+    findGraphShadowSnapshotByIntegrity,
     readGraphShadowSnapshot,
+    rememberGraphIdentityAlias,
     removeGraphShadowSnapshot,
+    resolveGraphIdentityAliasByHostChatId,
     shouldPreferShadowSnapshotOverOfficial,
     stampGraphPersistenceMeta,
     writeChatMetadataPatch,
     writeGraphShadowSnapshot,
     // Shadow snapshot functions need VM-local sessionStorage overrides
     // because imported versions use the outer globalThis (no sessionStorage)
+    rememberGraphIdentityAlias({
+      integrity = "",
+      hostChatId = "",
+      persistenceChatId = "",
+    } = {}) {
+      const normalizedIntegrity = String(integrity || "").trim();
+      if (!normalizedIntegrity) return null;
+
+      const normalizedHostChatId = String(hostChatId || "").trim();
+      const normalizedPersistenceChatId = String(
+        persistenceChatId || normalizedIntegrity,
+      ).trim();
+      let registry = { byIntegrity: {} };
+      try {
+        const raw = localStorage.getItem(GRAPH_IDENTITY_ALIAS_STORAGE_KEY);
+        if (raw) {
+          const parsed = JSON.parse(raw);
+          if (
+            parsed?.byIntegrity &&
+            typeof parsed.byIntegrity === "object" &&
+            !Array.isArray(parsed.byIntegrity)
+          ) {
+            registry = { byIntegrity: parsed.byIntegrity };
+          }
+        }
+      } catch {
+        registry = { byIntegrity: {} };
+      }
+
+      const current = registry.byIntegrity[normalizedIntegrity] || {};
+      const hostChatIds = Array.from(
+        new Set(
+          [
+            normalizedHostChatId,
+            ...(Array.isArray(current.hostChatIds) ? current.hostChatIds : []),
+          ].filter(Boolean),
+        ),
+      );
+      const next = {
+        integrity: normalizedIntegrity,
+        persistenceChatId: normalizedPersistenceChatId,
+        hostChatIds,
+        updatedAt: new Date().toISOString(),
+      };
+      registry.byIntegrity[normalizedIntegrity] = next;
+      localStorage.setItem(
+        GRAPH_IDENTITY_ALIAS_STORAGE_KEY,
+        JSON.stringify(registry),
+      );
+      return next;
+    },
+    resolveGraphIdentityAliasByHostChatId(hostChatId = "") {
+      const normalizedHostChatId = String(hostChatId || "").trim();
+      if (!normalizedHostChatId) return "";
+      try {
+        const raw = localStorage.getItem(GRAPH_IDENTITY_ALIAS_STORAGE_KEY);
+        const parsed = raw ? JSON.parse(raw) : { byIntegrity: {} };
+        let best = "";
+        let bestUpdatedAt = "";
+        for (const value of Object.values(parsed.byIntegrity || {})) {
+          const hostChatIds = Array.isArray(value?.hostChatIds)
+            ? value.hostChatIds.map((item) => String(item || "").trim())
+            : [];
+          if (!hostChatIds.includes(normalizedHostChatId)) continue;
+          const persistenceChatId = String(
+            value?.persistenceChatId || value?.integrity || "",
+          ).trim();
+          if (!persistenceChatId) continue;
+          const updatedAt = String(value?.updatedAt || "");
+          if (!best || updatedAt > bestUpdatedAt) {
+            best = persistenceChatId;
+            bestUpdatedAt = updatedAt;
+          }
+        }
+        return best;
+      } catch {
+        return "";
+      }
+    },
+    getGraphIdentityAliasCandidates({
+      integrity = "",
+      hostChatId = "",
+      persistenceChatId = "",
+    } = {}) {
+      const normalizedIntegrity = String(integrity || "").trim();
+      const normalizedHostChatId = String(hostChatId || "").trim();
+      const normalizedPersistenceChatId = String(
+        persistenceChatId || "",
+      ).trim();
+      const candidates = [];
+      const seen = new Set();
+      const addCandidate = (value) => {
+        const normalized = String(value || "").trim();
+        if (!normalized || seen.has(normalized)) return;
+        seen.add(normalized);
+        candidates.push(normalized);
+      };
+
+      try {
+        const raw = localStorage.getItem(GRAPH_IDENTITY_ALIAS_STORAGE_KEY);
+        const parsed = raw ? JSON.parse(raw) : { byIntegrity: {} };
+        if (normalizedIntegrity) {
+          const value = parsed.byIntegrity?.[normalizedIntegrity] || {};
+          addCandidate(value?.persistenceChatId || value?.integrity || "");
+          for (const candidate of Array.isArray(value?.hostChatIds)
+            ? value.hostChatIds
+            : []) {
+            addCandidate(candidate);
+          }
+        } else if (normalizedHostChatId) {
+          addCandidate(
+            runtimeContext.resolveGraphIdentityAliasByHostChatId(
+              normalizedHostChatId,
+            ),
+          );
+        }
+      } catch {
+        // ignore
+      }
+
+      addCandidate(normalizedHostChatId);
+      addCandidate(normalizedPersistenceChatId);
+      return candidates;
+    },
     readGraphShadowSnapshot(chatId = "") {
       const key = getGraphShadowSnapshotStorageKey(chatId);
       if (!key) return null;
@@ -286,6 +525,56 @@ async function createGraphPersistenceHarness({
         return null;
       }
     },
+    findGraphShadowSnapshotByIntegrity(integrity = "", { excludeChatIds = [] } = {}) {
+      const normalizedIntegrity = String(integrity || "").trim();
+      if (!normalizedIntegrity) return null;
+      const excluded = new Set(
+        (Array.isArray(excludeChatIds) ? excludeChatIds : [])
+          .map((value) => String(value || "").trim())
+          .filter(Boolean),
+      );
+      let best = null;
+      for (const key of storage.__store.keys()) {
+        if (!String(key || "").startsWith(GRAPH_SHADOW_SNAPSHOT_STORAGE_PREFIX)) {
+          continue;
+        }
+        try {
+          const snap = JSON.parse(storage.getItem(key));
+          if (
+            !snap ||
+            String(snap.integrity || "") !== normalizedIntegrity ||
+            typeof snap.serializedGraph !== "string" ||
+            !snap.serializedGraph
+          ) {
+            continue;
+          }
+          const normalizedChatId = String(snap.chatId || "").trim();
+          if (!normalizedChatId || excluded.has(normalizedChatId)) {
+            continue;
+          }
+          if (
+            !best ||
+            Number(snap.revision || 0) > Number(best.revision || 0) ||
+            (Number(snap.revision || 0) === Number(best.revision || 0) &&
+              String(snap.updatedAt || "") > String(best.updatedAt || ""))
+          ) {
+            best = {
+              chatId: normalizedChatId,
+              revision: Number.isFinite(snap.revision) ? snap.revision : 0,
+              serializedGraph: snap.serializedGraph,
+              updatedAt: String(snap.updatedAt || ""),
+              reason: String(snap.reason || ""),
+              integrity: String(snap.integrity || ""),
+              persistedChatId: String(snap.persistedChatId || ""),
+              debugReason: String(snap.debugReason || snap.reason || ""),
+            };
+          }
+        } catch {
+          // ignore
+        }
+      }
+      return best;
+    },
     writeGraphShadowSnapshot(
       chatId = "",
       graph = null,
@@ -350,6 +639,8 @@ async function createGraphPersistenceHarness({
       return true;
     },
     notifyExtractionIssue() {},
+    debugDebug() {},
+    debugLog() {},
     async runExtraction() {},
     getRequestHeaders() {
       return {};
@@ -394,24 +685,37 @@ async function createGraphPersistenceHarness({
     __contextImmediateSaveCalls: 0,
     buildGraphFromSnapshot,
     buildSnapshotFromGraph,
+    buildBmeDbName,
     scheduleUpload() {},
+    BmeDatabase: class {
+      constructor(dbChatId = "") {
+        this.chatId = String(dbChatId || "");
+      }
+      async open() {}
+      async close() {}
+      async exportSnapshot() {
+        return getIndexedDbSnapshotForChat(this.chatId);
+      }
+      async importSnapshot(snapshot) {
+        setIndexedDbSnapshotForChat(this.chatId, snapshot);
+        return {
+          revision: Number(snapshot?.meta?.revision) || 0,
+        };
+      }
+    },
     BmeChatManager: class {
       constructor() {
-        this._db = {
+        this._currentChatId = "";
+      }
+      _createDb(dbChatId = "") {
+        return {
           async exportSnapshot() {
-            if (runtimeContext.__indexedDbSnapshot) {
-              return structuredClone(runtimeContext.__indexedDbSnapshot);
-            }
-            return {
-              meta: { revision: 0, chatId: "" },
-              nodes: [],
-              edges: [],
-              tombstones: [],
-              state: { lastProcessedFloor: -1, extractionCount: 0 },
-            };
+            return getIndexedDbSnapshotForChat(dbChatId);
           },
           async importSnapshot(snapshot) {
-            runtimeContext.__indexedDbSnapshot = structuredClone(snapshot);
+            setIndexedDbSnapshotForChat(dbChatId, snapshot);
+            runtimeContext.__indexedDbSnapshot =
+              getIndexedDbSnapshotForChat(dbChatId);
             return {
               revision:
                 Number(snapshot?.meta?.revision) ||
@@ -420,19 +724,18 @@ async function createGraphPersistenceHarness({
             };
           },
           async getMeta(key, fallbackValue = 0) {
-            const snapshot = runtimeContext.__indexedDbSnapshot || {};
+            const snapshot = getIndexedDbSnapshotForChat(dbChatId) || {};
             if (!snapshot?.meta || !(key in snapshot.meta)) {
               return fallbackValue;
             }
             return snapshot.meta[key];
           },
           async getRevision() {
-            return (
-              Number(runtimeContext.__indexedDbSnapshot?.meta?.revision) || 0
-            );
+            const snapshot = getIndexedDbSnapshotForChat(dbChatId) || {};
+            return Number(snapshot?.meta?.revision) || 0;
           },
           async isEmpty() {
-            const snapshot = runtimeContext.__indexedDbSnapshot || {};
+            const snapshot = getIndexedDbSnapshotForChat(dbChatId) || {};
             const nodes = Array.isArray(snapshot?.nodes)
               ? snapshot.nodes.length
               : 0;
@@ -451,33 +754,44 @@ async function createGraphPersistenceHarness({
           },
           async importLegacyGraph(graph, options = {}) {
             const revision = Number(options?.revision) || 1;
-            runtimeContext.__indexedDbSnapshot = buildSnapshotFromGraph(graph, {
-              chatId: runtimeContext.__chatContext?.chatId || "",
+            const migratedSnapshot = buildSnapshotFromGraph(graph, {
+              chatId: dbChatId || runtimeContext.__chatContext?.chatId || "",
               revision,
               meta: {
                 migrationCompletedAt: Date.now(),
                 migrationSource: "chat_metadata",
               },
             });
+            setIndexedDbSnapshotForChat(dbChatId, migratedSnapshot);
+            runtimeContext.__indexedDbSnapshot =
+              getIndexedDbSnapshotForChat(dbChatId);
             return {
               migrated: true,
               revision,
               imported: {
-                nodes: runtimeContext.__indexedDbSnapshot.nodes.length,
-                edges: runtimeContext.__indexedDbSnapshot.edges.length,
+                nodes: runtimeContext.__indexedDbSnapshot?.nodes?.length || 0,
+                edges: runtimeContext.__indexedDbSnapshot?.edges?.length || 0,
                 tombstones:
-                  runtimeContext.__indexedDbSnapshot.tombstones.length,
+                  runtimeContext.__indexedDbSnapshot?.tombstones?.length || 0,
               },
             };
           },
           async markSyncDirty() {},
         };
       }
-      async getCurrentDb() {
-        return this._db;
+      async getCurrentDb(dbChatId = this._currentChatId) {
+        this._currentChatId = String(dbChatId || this._currentChatId || "");
+        runtimeContext.__indexedDbSnapshot = getIndexedDbSnapshotForChat(
+          this._currentChatId,
+        );
+        return this._createDb(this._currentChatId);
       }
-      async switchChat() {
-        return this._db;
+      async switchChat(dbChatId = "") {
+        this._currentChatId = String(dbChatId || "");
+        runtimeContext.__indexedDbSnapshot = getIndexedDbSnapshotForChat(
+          this._currentChatId,
+        );
+        return this._createDb(this._currentChatId);
       }
       async closeCurrent() {}
     },
@@ -544,11 +858,33 @@ result = {
     return globalThis.__chatContext;
   },
   setIndexedDbSnapshot(snapshot) {
-    globalThis.__indexedDbSnapshot = snapshot;
+    const activeChatId =
+      String(globalThis.__chatContext?.chatId || globalThis.__globalChatId || "");
+    if (activeChatId) {
+      globalThis.__indexedDbSnapshots.set(
+        activeChatId,
+        structuredClone(snapshot),
+      );
+    }
+    globalThis.__indexedDbSnapshot = structuredClone(snapshot);
   },
   getIndexedDbSnapshot() {
     return globalThis.__indexedDbSnapshot;
   },
+  setIndexedDbSnapshotForChat(chatId, snapshot) {
+    const normalizedChatId = String(chatId || "");
+    if (!normalizedChatId) return;
+    globalThis.__indexedDbSnapshots.set(
+      normalizedChatId,
+      structuredClone(snapshot),
+    );
+  },
+  getIndexedDbSnapshotForChat(chatId) {
+    const normalizedChatId = String(chatId || "");
+    if (!normalizedChatId) return null;
+    const snapshot = globalThis.__indexedDbSnapshots.get(normalizedChatId);
+    return snapshot ? structuredClone(snapshot) : null;
+  },
 };
       `,
     ].join("\n"),
@@ -708,7 +1044,10 @@ result = {
 
   assert.equal(result.synced, true);
   assert.equal(result.loadState, "loading");
-  assert.equal(harness.api.getCurrentGraph().historyState.chatId, "chat-late");
+  assert.equal(
+    harness.api.getCurrentGraph().historyState.chatId,
+    "chat-late-ready",
+  );
   assert.equal(harness.api.getGraphPersistenceState().dbReady, true);
   assert.equal(
     harness.api.getGraphPersistenceState().storagePrimary,