fixup! Base Browser strings

Bug 42211: Migrate new identity to Fluent.

Also change some strings to sentence case in en-US.

Also removed the hard-coded "Tor Browser", which is not appropriate in
base-browser (e.g. for Mullvad Browser).

browser/locales/en-US/browser/base-browser.ftl

@@ -11,20 +11,19 @@ language-notification-label-system = { -brand-short-name } has set your display
 language-notification-label = { -brand-short-name } has set your display language to { $language }.
 language-notification-button = Change Language…
 
-
 ## Fullscreen/maximization notification shown when letterboxing is disabled
 
 basebrowser-rfp-maximize-warning-message = Maximizing the browser window can allow websites to determine your monitor size, which can be used to track you. We recommend that you leave browser windows in their original default size.
 basebrowser-rfp-restore-window-size-button-label = Restore
 basebrowser-rfp-restore-window-size-button-ak = R
 
-
 ## Tooltip for the about:addons recommended badge
 
 basebrowser-addon-badge-recommended = Mozilla only recommends extensions that meet their standards for security and performance
 basebrowser-addon-badge-verified = Mozilla has reviewed this extension to meet their standards for security and performance
 
 ## Option to show or hide the NoScript extension button/item.
+
 basebrowser-addon-noscript-visibility-label = Toolbar button
 basebrowser-addon-noscript-visibility-show = Show
 basebrowser-addon-noscript-visibility-hide = Hide
@@ -35,3 +34,39 @@ basebrowser-addon-noscript-visibility-hide = Hide
 # $version (String) - The current browser version. E.g. "12.5.3".
 # $firefoxVersion (String) - The version number of Firefox the current browser is based on. E.g. "102.15.0esr".
 basebrowser-about-dialog-version = { $version } (based on Mozilla Firefox { $firefoxVersion })
+
+## New identity.
+
+# File menu items use title case for English (US).
+menu-new-identity =
+    .label = New Identity
+    .accesskey = I
+
+# App menu (hamburger menu) items use sentence case for English (US).
+appmenuitem-new-identity =
+    .label = New identity
+
+# Uses sentence case for English (US).
+# ".label" is the accessible name, and is visible in the overflow menu and when
+# customizing the toolbar.
+# ".tooltiptext" will be identical to the label.
+toolbar-new-identity =
+    .label = New identity
+    .tooltiptext = { toolbar-new-identity.label }
+
+## New identity dialog.
+
+new-identity-dialog-title = Reset your identity?
+new-identity-dialog-description = { -brand-short-name } will close all windows and tabs. All website sessions will be lost.
+new-identity-dialog-never-ask-checkbox =
+    .label = Never ask me again
+new-identity-dialog-confirm =
+    .label = Restart { -brand-short-name }
+
+## New identity: blocked home page notification.
+
+# '-brand-short-name' is the localized browser name, like "Tor Browser".
+# $url (String) - The URL of the home page, possibly shortened.
+new-identity-blocked-home-notification = { -brand-short-name } blocked your homepage ({ $url }) from loading because it might recognize your previous session.
+# Button to continue loading the home page, despite the warning message.
+new-identity-blocked-home-ignore-button = Load it anyway