feat(ui): revert indicator with undo/redo, message list, and attachment restore (#1279)

* feat(ui): revert indicator with undo/redo, message list, and attachment restore

Add bidirectional undo/redo with redo stack navigation and expandable
revert indicator in StatusRow. List reverted messages with inline
revert/fork actions. Restore file attachments on revert.

- Add revert indicator with count, expandable popover, per-button spinner
- Restore file/image attachments when reverting to a message
- Clear previous attachments on revert when target has none
- Restore-all bypasses redo stack for direct unrevert
- Survive popover close/reopen without losing loading state
- Fix flash when sending message after revert
- Fix count disappearing on browser refresh
- Remove dead code (undoStack, getRevertHistory, fork-from-here)
- Fix toast grammar (Undid -> Reverted, Redid -> Redone)
- Add i18n keys for revert popover across all locales

* fix(ui): Greptile review fixes and i18n for revert toasts

- Fix handleSlashUndo toast always showing [No text] (moved getSyncParts before revertToMessage)
- Add inputStore rollback in revertToMessage catch (restore attachments + text on API failure)
- Change portal ID to per-session (prevent multi-session collisions)
- Add i18n keys for undo/redo/restored toasts across all 7 locales
- Use formatMessage in store for localized toast strings

* fix(ui): add missing sessionId to click-outside effect deps

* fix(ui): remove unused sessionActions import in ChatMessage

* fix(ui): derive revert dock from session state

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Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/components/chat/StatusRow.tsx

@@ -288,8 +288,8 @@ export const StatusRow: React.FC<StatusRowProps> = ({
   return (
     <div className={cn("mb-1", !hasLeftAccessory && "chat-column")} style={STATUS_ROW_CONTAINER_STYLE}>
       <div className={cn("flex items-center justify-between py-0.5 gap-2 h-[1.2rem]", hasLeftAccessory && "px-0.5")}>
-        {/* Left: Abort status or Working placeholder or leftAccessory */}
-        <div className={cn("flex-1 flex items-center min-w-0", hasLeftAccessory ? "pl-1.5" : "overflow-hidden")}>
+        {/* Left: Abort status | Working placeholder | leftAccessory */}
+        <div className={cn("flex-1 flex items-center min-w-0 gap-2", hasLeftAccessory ? "pl-1.5" : "overflow-x-hidden")}>
           {showAssistantStatus && showAbortStatus ? (
             <div className="flex h-full items-center text-[var(--status-error)] pl-0.5">
               <span className="flex items-center gap-1.5 typography-ui-label">