feat(hub): chat, presence, a Profile page, and downloads that do not freeze

Chat opens on the newest hundred messages, loads fifty older on demand with the
reading position anchored — the distance from the *bottom*, since everything
above the viewport just grew — and follows new messages only when the reader was
already at the end. Day separators, sender grouping, an unread marker, and a
jump-to-latest pill. Messages are keyed by id: index keys plus prepending makes
Preact reuse the wrong bubbles.

A presence dot per group in the sidebar, three states, each backed by something:
the hub's registry, or a connection this browser made or failed to make. Never
colour alone — red and green are the pair colour-blind readers cannot separate —
so each dot carries a title and an aria-label.

Profile is split out of Settings: identity, node link, pinned node identities and
account deletion. Mixing them put an irreversible button two scrolls under a
theme picker. The create-group page loses its centred 520 px card, which left
190 px of margin either side, and its two button panels become a radio group —
a button conveys no chosen state to a screen reader, and side by side they read
as two independent actions rather than one either/or.

The Files toolbar shows its actions as icon buttons the moment Select is on,
disabled when they do not apply rather than appearing and vanishing. On a phone
the right-hand group could not wrap and ran 130 px off the screen.

Streamed downloads no longer freeze after one chunk. `registration.active` says
a worker exists, not that this page is controlled by it — and an uncontrolled
page's requests never reach its fetch handler, so the worker took the stream and
was never asked for it, leaving `writer.write()` waiting on backpressure that
would never lift. The page now requires control and the worker confirms it
actually served the request before the sink is trusted.

Fixed on the way: `setActionsOpen` outlived the state it belonged to and threw
on every Files action; the chat scrollbar stopped short of the bottom; the
owner's row sat lower than the rest; About showed a version hardcoded two
releases ago.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
index bfa6d05..40a40a4 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
@@ -373,4 +373,21 @@ export default {
     other: '找到 {n} 个文件',
   },
   'search.hint': '在所有已缓存的群组索引中搜索文件名。',
+
+  // Presence, chat paging, leaving a group, the profile page
+  'presence.online': '有一个服务本群组的 node 在线',
+  'presence.offline': '本群组没有可达的 node',
+  'presence.unknown': '尚未检测',
+  'chat.load_older': '加载更早的 {n} 条消息',
+  'chat.start_of_history': '对话开头',
+  'chat.today': '今天',
+  'chat.yesterday': '昨天',
+  'chat.unread': '新消息',
+  'chat.jump_latest': '跳到最新',
+  'chat.jump_new': '新消息',
+  'group.leave': '退出群组',
+  'group.leave_confirm': '退出“{name}”？您将失去其文件和聊天的访问权。您上传的文件仍留在 node 上，node 也会保留它为您固定的身份，直到其运营者将其移除。',
+  'profile.title': '个人资料',
+  'usermenu.profile': '个人资料',
+  'create_group.public_is_open': '任何人都可以找到并加入公开群组。若要挑选谁能进来，请创建为私密群组。',
 };