feat(chat): message-list rework, customization surface, smooth scroll

Chat tab overhaul:
- Header/layout: single-row header (name + key-lock + compact click-to-copy address +
  right-aligned icon toolbar with a settings "notch"), composer moved below the message
  box (emoji toggle left of a bottom-flush input), tightened list-pane controls.
- Message list: per-day date separators (Today/Yesterday/date), time-only group headers,
  tight same-sender grouping with iMessage-style merged corners, per-run peer avatar,
  delivery status (clock -> check), hover-reveal per-message time. Message base ~18px.
- Customization: a settings "notch" gear opens a modal (also under Settings ->
  Chat & Contacts) with segmented controls for emoji style / bubble style / density /
  timestamps, sliders for poll rate + text size, a bubble-accent dropdown, Enter-to-send.
  Bubble style/accent/density/text-size/timestamps all applied live in the message loop.
- Settings: app-wide clock-format control lives in Settings -> General; chat keeps a
  per-tab override. Both chat panes now use the app's smooth wheel-scroll.
- i18n: new strings across all 8 languages; CJK subset rebuilt for the added glyphs.

Inline contact rename, hide/mute, 0-conf fast-scan and the export path are carried through.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

res/lang/zh.json

@@ -135,12 +135,25 @@
     "change_pass_title": "更改密码短语",
     "characters": "字符",
     "chat": "聊天",
+    "chat_accent_amber": "琥珀色",
+    "chat_accent_blue": "蓝色",
+    "chat_accent_green": "绿色",
+    "chat_accent_pink": "粉色",
+    "chat_accent_purple": "紫色",
+    "chat_accent_theme": "主题",
     "chat_add_contact": "添加联系人",
     "chat_awaiting_key": "等待回复",
+    "chat_bubble_minimal": "极简",
+    "chat_bubble_rounded": "圆角",
+    "chat_bubble_square": "方形",
     "chat_cancel": "取消",
     "chat_contact_added": "已添加联系人——可在联系人中重命名",
     "chat_contact_request": "联系人请求",
     "chat_copy_address_tip": "点击复制地址",
+    "chat_density_comfortable": "宽松",
+    "chat_density_compact": "紧凑",
+    "chat_emoji_color": "彩色",
+    "chat_emoji_mono": "单色",
     "chat_emoji_search": "搜索表情",
     "chat_empty_hint": "暂无对话。您收到的消息将显示在此处。",
     "chat_empty_start": "点击\"新建会话\"开始。",
@@ -156,21 +169,39 @@
     "chat_len_over": "消息过长",
     "chat_locked_hint": "解锁钱包以加载您的聊天记录。",
     "chat_mute": "静音",
-    "chat_new_button": "新建对话",
+    "chat_new_button": "新聊天",
     "chat_new_message": "消息",
     "chat_new_message_toast": "新的加密聊天消息",
     "chat_new_send": "发送请求",
-    "chat_new_title": "新建对话",
+    "chat_new_title": "新聊天",
     "chat_new_zaddr": "收款方 z 地址",
     "chat_no_matches": "没有与搜索匹配的会话。",
     "chat_no_z_contacts": "暂无使用隐私地址的联系人",
+    "chat_opt_bubble_accent": "气泡颜色",
+    "chat_opt_bubble_style": "气泡样式",
+    "chat_opt_density": "消息密度",
+    "chat_opt_emoji": "表情样式",
+    "chat_opt_enter_sends": "回车发送消息",
+    "chat_opt_font_size": "文字大小",
+    "chat_opt_global_clock": "全局时间格式",
+    "chat_opt_poll": "轮询频率",
+    "chat_opt_timestamp": "时间戳",
     "chat_pick_contact": "从联系人中选择…",
+    "chat_rename": "重命名联系人",
+    "chat_rename_hint": "联系人名称",
+    "chat_renamed": "联系人已重命名",
     "chat_retry": "重试",
     "chat_search": "搜索会话",
+    "chat_sec_appearance": "外观",
+    "chat_sec_messaging": "消息",
     "chat_select_hint": "选择一个对话以查看。",
     "chat_send": "发送",
     "chat_send_failed": "未发送",
     "chat_sending": "发送中…",
+    "chat_settings_done": "完成",
+    "chat_settings_section": "聊天与联系人",
+    "chat_settings_tip": "聊天自定义",
+    "chat_settings_title": "聊天设置",
     "chat_show_hidden": "显示已隐藏",
     "chat_time_now": "刚刚",
     "chat_toast_compose_failed": "无法编写该消息（内容过长？）。",
@@ -181,10 +212,16 @@
     "chat_toast_request_compose_failed": "无法编写联系人请求（地址或文本无效？）。",
     "chat_toast_request_queued": "联系人请求已排队。",
     "chat_toast_waiting_reply": "等待该联系人回复——对方回复后您即可向其发送消息。",
+    "chat_today": "今天",
+    "chat_ts_12h": "12小时",
+    "chat_ts_24h": "24小时",
+    "chat_ts_global": "跟随全局",
+    "chat_ts_global_short": "全局",
     "chat_unhide": "取消隐藏",
     "chat_unmute": "取消静音",
     "chat_verify_key": "身份密钥 — 对比以验证",
     "chat_waiting_reply": "等待该联系人回复——对方回复后您即可向其发送消息。",
+    "chat_yesterday": "昨天",
     "chat_you": "我",
     "choose_icon": "选择图标",
     "clear": "清除",
@@ -196,6 +233,7 @@
     "click_copy_address": "点击复制地址",
     "click_copy_uri": "点击复制 URI",
     "click_to_copy": "点击复制",
+    "clock_format": "时间格式",
     "close": "关闭",
     "conf_count": "%d 确认",
     "confirm_and_send": "确认并发送",
@@ -1388,6 +1426,7 @@
     "tt_change_pass": "更改钱包加密密码",
     "tt_change_pin": "更改您的解锁 PIN",
     "tt_clear_ztx": "删除本地缓存的 z-交易历史",
+    "tt_clock_format": "24 或 12 小时制，应用全局。聊天可覆盖。",
     "tt_custom_fees": "发送交易时启用手动费用输入",
     "tt_custom_theme": "自定义主题已激活",
     "tt_daemon_install_bundled": "停止节点，用此钱包版本内置的 dragonxd 覆盖已安装的版本，然后重启",