feat: per-account All Mail folder selection

Replaces the global allMailFolderIds (string[] | null) with a per-account
Record<accountId, string[]>, so each account chooses which of its own folders
the "All Mail" view merges. A missing entry = "not configured" (defaults to
every no-role folder); an explicit [] = "no folders".

- settings-store: type/default -> Record (default {}); persist version 4 -> 5,
  migration drops the legacy global list (the active account isn't known at
  migrate time); onRehydrate + importSettings coerce/ignore any non-record
  (legacy global string[] | null) shape. isPlainRecord() guard.
- email-store.resolveAllMailJmapIds: reads the entry for the account the view is
  scoped to (viewingAccountId ?? activeAccountId); undefined -> all no-role,
  [] -> none.
- layout-settings: read/write the active account's entry; when more than one
  account is logged in, an italic hint names the account the selection applies
  to (settings.appearance.all_mail.account_hint, 19 locales; de/ro translated).
- Test: stores/__tests__/settings-store-all-mail.test.ts (per-account
  independence, explicit-empty vs not-configured, importSettings legacy guard).

components/settings/layout-settings.tsx

@@ -121,24 +121,37 @@ export function LayoutSettings() {
   const { toolbarPosition, showToolbarLabels, hideAccountSwitcher, showRailAccountList, enableUnifiedMailbox, includeGroupInUnified, enableAllMailView, allMailFolderIds, colorfulSidebarIcons, mailLayout, proInterface, updateSetting } = useSettingsStore();
   const { isSettingLocked, isSettingHidden, isFeatureEnabled } = usePolicyStore();
   const accounts = useAccountStore(s => s.accounts);
+  const activeAccountId = useAccountStore(s => s.activeAccountId);
   const mailboxes = useEmailStore(s => s.mailboxes);
   const hasGroupInboxes = useMemo(() => mailboxes.some(m => m.isShared), [mailboxes]);
   const allMailViewAllowed = isFeatureEnabled('allMailViewEnabled');
 
-  // Own (non-shared) folders and the current All Mail selection. `null` =
+  // Own (non-shared) folders and the active account's All Mail selection. The
-  // never configured, which defaults to all non-special (no-role) folders.
+  // selection is per account: a missing entry = never configured, which
+  // defaults to all no-role folders; an explicit [] = no folders.
   const ownMailboxes = useMemo(() => mailboxes.filter(m => !m.isShared), [mailboxes]);
+  const currentAllMailEntry = activeAccountId ? allMailFolderIds[activeAccountId] : undefined;
   const allMailSelected = new Set(
-    allMailFolderIds === null
+    currentAllMailEntry === undefined
       ? ownMailboxes.filter(m => !m.role).map(m => m.id)
-      : allMailFolderIds
+      : currentAllMailEntry
   );
   const toggleAllMailFolder = (id: string) => {
+    if (!activeAccountId) return;
     const next = new Set(allMailSelected);
     if (next.has(id)) next.delete(id);
     else next.add(id);
-    updateSetting('allMailFolderIds', ownMailboxes.filter(m => next.has(m.id)).map(m => m.id));
+    updateSetting('allMailFolderIds', {
+      ...allMailFolderIds,
+      [activeAccountId]: ownMailboxes.filter(m => next.has(m.id)).map(m => m.id),
+    });
   };
+  // Name the account the selection applies to, but only when more than one is
+  // logged in (otherwise it's unambiguous).
+  const activeAccount = accounts.find(a => a.id === activeAccountId);
+  const allMailAccountHint = accounts.length > 1 && activeAccount
+    ? t('all_mail.account_hint', { account: activeAccount.displayName || activeAccount.email })
+    : null;
 
   return (
     <SettingsSection title={t('title')} description={t('description')}>
@@ -244,6 +257,9 @@ export function LayoutSettings() {
           <div>
             <div className="text-sm font-medium text-foreground">{t('all_mail.folders_label')}</div>
             <div className="text-xs text-muted-foreground">{t('all_mail.folders_description')}</div>
+            {allMailAccountHint && (
+              <div className="text-xs italic text-muted-foreground mt-0.5">{allMailAccountHint}</div>
+            )}
           </div>
           {ownMailboxes.length === 0 ? (
             <p className="text-xs text-muted-foreground">{t('all_mail.no_folders')}</p>

locales/cs/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/da/common.json

@@ -922,6 +922,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/de/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Gilt für {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/en/common.json

@@ -922,6 +922,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/es/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/fr/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/hu/common.json

@@ -922,6 +922,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/it/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/ja/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/ko/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/lv/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/nl/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/pl/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/pt/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/ro/common.json

@@ -922,6 +922,7 @@
         "description": "Afișați o intrare „Toate mesajele” deasupra folderelor, care reunește mesajele din toate folderele acestui cont într-o singură listă.",
         "folders_label": "Dosare în „Toate mesajele”",
         "folders_description": "Alegeți ce dosare să fie incluse în vizualizarea „Toate mesajele”.",
+        "account_hint": "Se aplică pentru {account}.",
         "no_folders": "Nu sunt disponibile foldere."
       },
       "colorful_sidebar_icons": {

locales/ru/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/tr/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/uk/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

locales/zh/common.json

@@ -919,6 +919,7 @@
         "description": "Show an \"All Mail\" entry above your folders that merges messages from across this account's folders into one list.",
         "folders_label": "Folders in All Mail",
         "folders_description": "Choose which folders are merged into the All Mail view.",
+        "account_hint": "Applies to {account}.",
         "no_folders": "No folders available."
       },
       "colorful_sidebar_icons": {

stores/__tests__/settings-store-all-mail.test.ts

@@ -0,0 +1,55 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { useSettingsStore } from '../settings-store';
+
+describe('settings-store per-account allMailFolderIds', () => {
+  beforeEach(() => {
+    useSettingsStore.setState({ allMailFolderIds: {} });
+  });
+
+  it('defaults to an empty record (every account "not configured")', () => {
+    expect(useSettingsStore.getState().allMailFolderIds).toEqual({});
+  });
+
+  it('keeps each account selection independent', () => {
+    useSettingsStore.setState({
+      allMailFolderIds: { 'acct-1': ['inbox', 'archive'], 'acct-2': ['sent'] },
+    });
+    const map = useSettingsStore.getState().allMailFolderIds;
+    expect(map['acct-1']).toEqual(['inbox', 'archive']);
+    expect(map['acct-2']).toEqual(['sent']);
+    // A third account remains unconfigured (no entry).
+    expect(map['acct-3']).toBeUndefined();
+  });
+
+  it('distinguishes explicit-empty ([] = no folders) from not-configured (undefined)', () => {
+    useSettingsStore.setState({ allMailFolderIds: { 'acct-1': [] } });
+    const map = useSettingsStore.getState().allMailFolderIds;
+    expect(map['acct-1']).toEqual([]);          // explicit "no folders"
+    expect(map['acct-2']).toBeUndefined();      // never configured
+  });
+
+  describe('importSettings legacy-shape guard', () => {
+    it('ignores a legacy global array shape', () => {
+      useSettingsStore.setState({ allMailFolderIds: { 'acct-1': ['inbox'] } });
+      const ok = useSettingsStore.getState().importSettings(
+        JSON.stringify({ allMailFolderIds: ['inbox', 'sent'] }),
+      );
+      expect(ok).toBe(true);
+      // unchanged - the array shape was rejected
+      expect(useSettingsStore.getState().allMailFolderIds).toEqual({ 'acct-1': ['inbox'] });
+    });
+
+    it('ignores a null legacy value', () => {
+      useSettingsStore.setState({ allMailFolderIds: { 'acct-1': ['inbox'] } });
+      useSettingsStore.getState().importSettings(JSON.stringify({ allMailFolderIds: null }));
+      expect(useSettingsStore.getState().allMailFolderIds).toEqual({ 'acct-1': ['inbox'] });
+    });
+
+    it('accepts a proper per-account record', () => {
+      useSettingsStore.getState().importSettings(
+        JSON.stringify({ allMailFolderIds: { 'acct-9': ['inbox', 'spam'] } }),
+      );
+      expect(useSettingsStore.getState().allMailFolderIds).toEqual({ 'acct-9': ['inbox', 'spam'] });
+    });
+  });
+});

stores/email-store.ts

@@ -321,15 +321,19 @@ function resolveActionMailboxes(): Mailbox[] {
 
 /**
  * Resolves the JMAP mailbox ids that make up the gated "All Mail" view for the
- * active/viewing account. Honors the per-user `allMailFolderIds` setting; when
+ * active/viewing account. Honors that account's `allMailFolderIds` entry; when
- * unset (null) it defaults to every non-special (no-role) folder. Shared
+ * not configured it defaults to every non-special (no-role) folder. Shared
  * folders are excluded - All Mail is scoped to a single account. Returns
  * JMAP-side ids (originalId for namespaced mailboxes).
  */
 function resolveAllMailJmapIds(): string[] {
   const mailboxes = resolveActionMailboxes().filter((mb) => !mb.isShared);
-  const configured = useSettingsStore.getState().allMailFolderIds;
+  // Per-account selection: read the entry for the account the view is scoped to
-  const selected = configured === null
+  // (the Pro viewing override, else the global active account). A missing entry
+  // = "not configured" -> all no-role folders; an explicit [] = no folders.
+  const accountId = useEmailStore.getState().viewingAccountId ?? useAuthStore.getState().activeAccountId;
+  const configured = accountId ? useSettingsStore.getState().allMailFolderIds[accountId] : undefined;
+  const selected = configured === undefined
     ? mailboxes.filter((mb) => !mb.role)
     : mailboxes.filter((mb) => configured.includes(mb.id));
   return selected.map((mb) => mb.originalId || mb.id);

stores/settings-store.ts

@@ -15,6 +15,11 @@ const syncLog = (...args: unknown[]) => console.log('[SETTINGS_SYNC]', ...args);
 const syncWarn = (...args: unknown[]) => console.warn('[SETTINGS_SYNC]', ...args);
 const syncError = (...args: unknown[]) => console.error('[SETTINGS_SYNC]', ...args);
 
+/** True for a non-null, non-array plain object (the allMailFolderIds map shape). */
+function isPlainRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
 // Settings sync state (module-level, not persisted)
 let syncEnabled = false;
 let syncUsername: string | null = null;
@@ -221,7 +226,10 @@ interface SettingsState {
   // configured, in which case the view defaults to all non-special (no-role)
   // folders of the active account.
   enableAllMailView: boolean;
-  allMailFolderIds: string[] | null;
+  // Per-account "All Mail" folder selection, keyed by AccountEntry.id. A
+  // missing entry = "not configured" -> defaults to every no-role folder; an
+  // explicit [] = "no folders". (Replaced the legacy global string[] | null.)
+  allMailFolderIds: Record<string, string[]>;
 
   // Email Display
   disableThreading: boolean; // Show emails as individual messages instead of grouped by conversation
@@ -409,7 +417,7 @@ const DEFAULT_SETTINGS = {
 
   // All Mail view (gated)
   enableAllMailView: false,
-  allMailFolderIds: null as string[] | null,
+  allMailFolderIds: {} as Record<string, string[]>,
 
   // Email Display
   disableThreading: false,
@@ -633,6 +641,11 @@ export const useSettingsStore = create<SettingsState>()(
                 set({ sendDelaySeconds: 0 });
                 return;
               }
+              // Ignore a legacy global allMailFolderIds (string[] | null) or any
+              // non-record value - this build keys it per account.
+              if (key === 'allMailFolderIds' && !isPlainRecord(settings[key])) {
+                return;
+              }
               if (DEVICE_LOCAL_SETTING_KEYS.has(key)) {
                 return;
               }
@@ -823,7 +836,7 @@ export const useSettingsStore = create<SettingsState>()(
     }),
     {
       name: 'settings-storage',
-      version: 4,
+      version: 5,
       migrate: (persisted, version) => {
         const state = persisted as Record<string, unknown>;
         if (version < 2 && state.listDensity) {
@@ -843,11 +856,25 @@ export const useSettingsStore = create<SettingsState>()(
         if (version < 4) {
           state.dateFormat = 'smart';
         }
+        // v5: allMailFolderIds went from a global `string[] | null` to a
+        // per-account `Record<accountId, string[]>`. The legacy global list
+        // can't be attributed to a specific account here (the active account
+        // isn't known at migrate time), so it's dropped - each account starts
+        // "not configured" (defaults to all no-role folders).
+        if (version < 5 || !isPlainRecord(state.allMailFolderIds)) {
+          state.allMailFolderIds = {};
+        }
         return state as unknown as SettingsState;
       },
       onRehydrateStorage: () => {
         return (state) => {
           if (state) {
+            // Defensive: a legacy global array or any non-record value (e.g.
+            // synced from an older client) is coerced to an empty map so
+            // per-account consumers never see a non-record.
+            if (!isPlainRecord(state.allMailFolderIds)) {
+              state.allMailFolderIds = {};
+            }
             applyFontSize(state.fontSize);
             applyDensity(state.density);
             applyAnimations(state.animationsEnabled);