[Feature Request] Add Chinese (中文) UI localization for the Web Viewer

[github-actions[bot]]

Originally posted as issue #2367 by @SilverKurali
#2367

Summary

The Web Viewer (http://localhost:37777) currently displays entirely in English.
While the memory engine itself supports Chinese mode via CLAUDE_MEM_MODE=code--zh,
the web interface has no localization support.

Motivation

Claude-mem has a significant user base in China and other Chinese-speaking regions
(visible from GitHub traffic and community activity). A Chinese UI would substantially
improve usability for these users without requiring them to mentally translate every label,
button, and status message.

Proposed Solution

Add i18n support to the Web Viewer with at minimum a Simplified Chinese (zh-CN) locale,
covering:

• Navigation labels and tab titles
• Memory entry metadata (session, timestamp, type labels)
• Search input placeholder and result messages
• Status indicators and empty states
• Error and loading messages

A language toggle in the header (or auto-detect via browser Accept-Language) would be ideal.

Notes

• The core engine already ships a code--zh mode, so Chinese terminology conventions
  are already established — the UI strings just need to follow suit.
• Even a minimal static translation file (e.g. locales/zh-CN.json) would be a great
  starting point if a full i18n framework is too heavy.

Environment

• OS: Windows 11/Arch-Linux(CatOS)
• claude-mem version: latest
• Browser: Chrome

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This is a feature request, not a bug. Happy to help with translation strings if a
contributor opens a PR for the i18n infrastructure.