feat: let the operator pause and resume a root's indexing (MNP 6.2)

A whole-root walk now checks its root before every file: removed or
ejected, it stops instead of reading the drive to the end; paused, it
finishes from the hash cache alone. A paused root is not watched, not
swept by reconcile and survives a restart (roster), its indexed files
stay served. Resume runs the reconcile sweep over the root, so entries
and their enrichment are kept.

Signed root_pause / root_resume over MNP, loopback routes, CLI
`root pause|resume`, a pause button on the indexing dock and
pause/resume in the roots table of Group settings.

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

1 files changed, 25 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/roster.py b/packages/meshbay-node/src/meshbay_node/roster.py
index a5d1967..9336e38 100644
--- a/packages/meshbay-node/src/meshbay_node/roster.py
+++ b/packages/meshbay-node/src/meshbay_node/roster.py
@@ -737,6 +737,31 @@ class Roster:
         return {r["key"][len(prefix):] for r in rows
                 if r["key"].startswith(prefix) and r["value"] == "auto"}
 
+    # Whether the operator paused a root's indexing. Kept here beside
+    # `root_ejected:` for the same reasons: runtime state rather than
+    # configuration, and a pause that a restart undid would start the very scan
+    # the operator stopped.
+    SETTING_ROOT_PAUSED_PREFIX = "root_paused:"
+
+    @classmethod
+    def root_paused_key(cls, root_name: str) -> str:
+        return cls.SETTING_ROOT_PAUSED_PREFIX + fold(root_name)
+
+    async def set_root_paused(self, group_id: str, root_name: str,
+                              paused: bool, set_by: str = "") -> None:
+        await self.set_setting(group_id, self.root_paused_key(root_name),
+                               "1" if paused else "0", set_by)
+
+    async def paused_roots(self, group_id: str) -> set[str]:
+        """The folded names of this group's paused roots — matched like `ejected_roots`."""
+        prefix = self.SETTING_ROOT_PAUSED_PREFIX
+        async with self._db.execute(
+                "SELECT key, value FROM group_settings WHERE group_id = ?",
+                (group_id,)) as cur:
+            rows = await cur.fetchall()
+        return {r["key"][len(prefix):] for r in rows
+                if r["key"].startswith(prefix) and r["value"] == "1"}
+
     async def get_setting(self, group_id: str, key: str,
                           default: str | None = None) -> str | None:
         async with self._db.execute(