feat(node): persistent index cache, visible scan progress, adaptive reconcile, and delta sync

Indexer performance work, in four parts:

- Persistent (path, size, mtime) -> hash cache (indexer/cache.py) so a node
  restart no longer re-hashes every file — measured at 23 minutes for a
  114 GB library on a slow disk before this, near-instant after. Hashing
  is deliberately kept sequential (max_workers=1): it was never actually
  concurrent despite the pool size, and two interleaved reads seek-thrash
  a spinning disk instead of going faster.

- Byte-based scan progress (IndexProgress), surfaced via the loopback
  index-status route, the handshake ack, and a periodic INDEX_PROGRESS
  push to connected peers — drives a progress bar in the Create Group
  wizard and "add a directory" in Settings, and an animated presence dot.
  Guaranteed to settle back to idle via try/finally and a final push on
  the scanning->false transition.

- The reconcile backstop's directory walks now run in the executor
  instead of blocking the daemon's event loop; its interval defaults to
  10 min (was 60s) with adaptive backoff to 2h when nothing changes,
  reset on a real change or a peer connecting, and is now a per-group
  operator setting (signed op + group Settings UI).

- INDEX_DELTA wired up (protocol support existed, nothing called it):
  _on_index_change now sends additions/deletions instead of rebuilding
  the full entries list, coalesced over a short window so a burst of
  file events produces one push, and the hub swarm registration for
  public groups only (re-)registers newly added hashes.

Also fixes several bugs found while testing the above against real
libraries (a 114 GB and a 100+ GB group on a USB HDD):

- /api/reload blocked until the reload — including a brand-new group's
  full initial scan — finished, which the Electron bridge's fixed 30s
  call timeout turned into a hard failure on any real library. The route
  now fires the reload without waiting (ops.start_reload), matching
  add_root/remove_root's existing pattern; the wizard's own step order
  was fixed to wait for the group to actually appear hosted before the
  steps that need it (extra roots, GEK), with retries for the residual
  race between that and the daemon's own bookkeeping.
- transport.js's hand-rolled msgpack codec had no case for uint64/int64
  (0xcf/0xd3) and crashed decoding any message containing one — hit by
  IndexProgress.scanned_bytes/total_bytes for any group over ~4.3 GB.
  Verified against real msgpack-encoded bytes from the Python side.
- chat_hist_resp, and this change's own index_progress and
  set_scan_settings_ack pushes, were not routed by message type and
  could be handed to an unrelated pending request by the transport's
  "oldest pending" fallback, stalling it until its own 30s timeout and
  corrupting whatever received the wrong reply in its place.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016SF6RKNBKg9qejmoMJ9ybA

1 files changed, 11 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 0151c4b..ad8bf53 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
@@ -428,6 +428,7 @@ export default {
   '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',
+  'presence.indexing': '正在索引 — {pct}%',
   'chat.load_older': '加载更早的 {n} 条消息',
   'chat.start_of_history': '对话开头',
   'chat.today': '今天',
@@ -543,6 +544,13 @@ export default {
   // Settings — node
   'settings_node.detach_failed_continue': '无法从 node 上分离此群组。是否仍然在 hub 上删除？',
   'settings_node.roots': '共享目录',
+  'settings_node.scan_title': '扫描',
+  'settings_node.scan_hint': 'node 多久重新检查一次目录以发现可能错过的变化，以及文件变化后等待多久才建立索引。',
+  'settings_node.scan_reconcile_label': '重新检查间隔（分钟）',
+  'settings_node.scan_debounce_label': '变化后的等待时间（秒）',
+  'settings_node.scan_save': '保存',
+  'settings_node.scan_saving': '保存中…',
+  'settings_node.scan_saved': '已保存。',
 
   // Create group wizard
   'wizard.title': '创建群组',
@@ -566,6 +574,9 @@ export default {
   'wizard.step_add_roots': '添加目录',
   'wizard.step_gek': '初始化加密密钥',
   'wizard.step_pair': '设置配对',
+  'wizard.step_index': '正在索引文件',
+  'wizard.indexing_progress': '正在索引… {pct}%',
+  'wizard.indexing_current_dir': '正在扫描：{dir}',
   'wizard.done_title': '群组已创建',
   'wizard.done_message': '您的群组已就绪。您的 node 正在托管它，加密已设置完成。',
   'wizard.go_to_group': '前往群组',