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, 59 insertions, 1 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ops.py b/packages/meshbay-node/src/meshbay_node/ops.py
index c9d862a..154813d 100644
--- a/packages/meshbay-node/src/meshbay_node/ops.py
+++ b/packages/meshbay-node/src/meshbay_node/ops.py
@@ -22,6 +22,7 @@ in the adapter.
 
 from __future__ import annotations
 
+import asyncio
 import logging
 import re
 from dataclasses import asdict
@@ -730,12 +731,69 @@ async def set_enabled_apps(state: dict, group_id: str, apps: list[str]) -> dict:
     return {"apps": apps, "group_id": group_id}
 
 
+# ── Scan settings ────────────────────────────────────────────────────────────
+
+async def set_scan_settings(state: dict, group_id: str, reconcile_interval_secs: float,
+                            debounce_secs: float) -> dict:
+    """
+    How often the indexer's reconciliation backstop runs, and how long a
+    changed file is left alone before being hashed (indexer.py
+    DirectoryIndexer). Persisted like set_member_upload/set_enabled_apps —
+    but there is also a *live* DirectoryIndexer object to update, since it
+    reads these once at construction and runs its own background loop with
+    them rather than consulting groups_ctx on every use.
+    """
+    roster = _roster(state)
+    await roster.set_scan_settings(group_id, reconcile_interval_secs, debounce_secs,
+                                   set_by=state.get("node_user_id", ""))
+    indexer = state.get("indexers", {}).get(group_id)
+    if indexer:
+        indexer.reconcile_secs = reconcile_interval_secs
+        indexer.debounce_secs = debounce_secs
+        # Apply the new interval now rather than after whatever backoff had
+        # already stretched the wait to.
+        indexer.note_activity()
+    # Optional, unlike _group_ctx(): a group can be persisted here before it
+    # is hot-loaded (or in a test that only cares about the roster/indexer
+    # side), and that must not turn a successful write into a 404.
+    ctx = state.get("groups_ctx", {}).get(group_id)
+    if ctx is not None:
+        ctx["reconcile_interval_secs"] = reconcile_interval_secs
+        ctx["debounce_secs"] = debounce_secs
+    log.info("Scan settings for group %s: reconcile=%.0fs debounce=%.0fs",
+             group_id[:8], reconcile_interval_secs, debounce_secs)
+    return {"reconcile_interval_secs": reconcile_interval_secs,
+            "debounce_secs": debounce_secs, "group_id": group_id}
+
+
 # ── Reload ──────────────────────────────────────────────────────────────────
 
 async def reload_config(state: dict) -> dict:
-    """Hot-reload node.toml without dropping connections."""
+    """Hot-reload node.toml without dropping connections. Blocks until the
+    reload actually finishes — see start_reload for why the loopback route
+    uses that instead."""
     reload_fn = state.get("reload_fn")
     if not reload_fn:
         raise OpError("Reload not available", status=503)
     await reload_fn()
     return {"status": "reloaded"}
+
+
+async def start_reload(state: dict) -> dict:
+    """
+    Same as reload_config, but does not wait for the reload to finish.
+
+    The loopback route uses this one: the Electron bridge caps every call at
+    a fixed 30s (main.js node:call), and hot-loading a brand-new group runs
+    its full initial scan synchronously inside _reload_config_inner()
+    (daemon.py) before that coroutine returns — minutes, not seconds, on a
+    real library (found against a 45 GB group on the same slow disk the
+    StarWars benchmark used). The reload keeps running on the daemon's own
+    event loop either way; add_root/remove_root below already fire it the
+    same way for exactly this reason.
+    """
+    reload_fn = state.get("reload_fn")
+    if not reload_fn:
+        raise OpError("Reload not available", status=503)
+    asyncio.ensure_future(reload_fn())
+    return {"status": "reloading"}