fix(node): plug an auto-ejected removable root back once its files return

A node started with the desktop session runs before the session has mounted
its USB drives. The safety net then auto-ejected every removable root and
persisted it exactly like an operator's eject, so after each reboot those
roots stayed ejected until someone plugged them by hand (seen on a node whose
/media drives were mounted a minute after it started).

An auto-eject is now stored as such ("auto" in roster.db). At startup and at
every reconcile, an auto-ejected root whose path is readable again is checked
against a few files the hash cache knows under it, at the same path with the
same size and mtime; one found and the root is plugged back and rescanned.
An empty mount point or another drive in its place is not recognised and
stays ejected. An operator's eject is never undone automatically.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/indexer/cache.py b/packages/meshbay-node/src/meshbay_node/indexer/cache.py
index 6c87f40..5e328ef 100644
--- a/packages/meshbay-node/src/meshbay_node/indexer/cache.py
+++ b/packages/meshbay-node/src/meshbay_node/indexer/cache.py
@@ -23,6 +23,7 @@ only daemon.py's wiring changed.
 """
 
 import logging
+import os
 import time
 from dataclasses import dataclass
 from pathlib import Path
@@ -191,6 +192,19 @@ class IndexCache:
             row = await cur.fetchone()
         return row[0] if row else 0
 
+    async def sample_under(self, directory: str, limit: int) -> list[tuple[str, int, float]]:
+        """Up to `limit` cached files under `directory`, as (path, size, mtime).
+
+        A prefix compared with `substr`, not `LIKE`: `_` and `%` are wildcards
+        there, and both are ordinary in a folder name.
+        """
+        prefix = directory.rstrip("/\\") + os.sep
+        async with self._db.execute(
+                "SELECT path, size, mtime FROM files WHERE substr(path, 1, ?) = ? LIMIT ?",
+                (len(prefix), prefix, limit)) as cur:
+            rows = await cur.fetchall()
+        return [(row[0], row[1], row[2]) for row in rows]
+
     async def all_paths(self) -> list[str]:
         """Every cached path, for a caller that decides staleness itself —
         this cache has no notion of which paths are still claimed by a