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, 53 insertions, 9 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/index-dock.js b/packages/meshbay-hub/src/meshbay_hub/static/index-dock.js
index 6c89eb6..47a5818 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/index-dock.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/index-dock.js
@@ -6,7 +6,7 @@ import { navigate, session } from './hub-client.js';
 import { useStickyBand } from './sticky.js';
 import { Icon } from './icon.js';
 import {
-  fromLoopback, fromPush, mergeActivity, dockRows, hideRow, percent, queuedCount,
+  fromLoopback, fromPush, mergeActivity, dockRows, hideRow, pauseRow, percent, queuedCount,
 } from './index-dock-model.js';
 
 // ── Indexing dock ───────────────────────────────────────────────────────────
@@ -29,6 +29,9 @@ const ABSENT_POLL_MS = 30000;
 // rather than a prop through App: the page and the dock are far apart, and a
 // push every two seconds must not re-render the whole application.
 const pushed = new Map();
+// How to pause a root of that group over the page's connection, signed by its
+// operator — the dock holds no transport of its own.
+const pushedPause = new Map();
 const listeners = new Set();
 
 /**
@@ -36,11 +39,17 @@ const listeners = new Set();
  * member keeps the sidebar dot. `status` is the push (or the handshake ack's
  * `indexing`); `roots` the roots table the page opened, which names `root_pos`.
  * `null` when the page lets go of the group: nothing will update the entry any
- * more, and a stale "scanning" would stay on screen for ever.
+ * more, and a stale "scanning" would stay on screen for ever. `pause(rootName)`
+ * is what the row's pause button calls when no node answers on this machine.
  */
-export function reportIndexPush(groupId, status, roots) {
-  if (status) pushed.set(groupId, fromPush(groupId, status, roots));
-  else pushed.delete(groupId);
+export function reportIndexPush(groupId, status, roots, pause) {
+  if (status) {
+    pushed.set(groupId, fromPush(groupId, status, roots));
+    if (pause) pushedPause.set(groupId, pause);
+  } else {
+    pushed.delete(groupId);
+    pushedPause.delete(groupId);
+  }
   for (const fn of listeners) fn();
 }
 
@@ -96,7 +105,7 @@ function usePushedActivity() {
   return snapshot;
 }
 
-function DockRow({ row, onOpen, onHide }) {
+function DockRow({ row, error, onOpen, onPause, onHide }) {
   const done = row.state === 'done';
   const waiting = !done && !row.scanning;
   const listing = !done && row.scanning && !row.totalBytes;
@@ -109,7 +118,9 @@ function DockRow({ row, onOpen, onHide }) {
   const where = row.root ? `${row.groupName} › ${row.root}` : row.groupName;
 
   let meta = '';
-  if (listing) {
+  if (error) {
+    meta = error;
+  } else if (listing) {
     meta = t('indexdock.listing');
   } else if (!done && !waiting) {
     meta = [
@@ -133,7 +144,8 @@ function DockRow({ row, onOpen, onHide }) {
         onClick=${onOpen}>
         <span class="index-dock-head">
           <span class="index-dock-title"><strong>${status}</strong> ${where}</span>
-          ${meta && html`<span class="index-dock-meta">${meta}</span>`}
+          ${meta && html`<span class="index-dock-meta ${error ? 'index-dock-error' : ''}"
+            role=${error ? 'alert' : null}>${meta}</span>`}
         </span>
         <span class="index-progress-bar index-dock-bar">
           <span class="index-progress-fill ${moving ? 'index-dock-indeterminate' : ''}"
@@ -141,6 +153,12 @@ function DockRow({ row, onOpen, onHide }) {
         </span>
         ${next && html`<span class="index-dock-next">${next}</span>`}
       </button>
+      ${!done && onPause && html`
+        <button type="button" class="index-dock-hide" title=${t('indexdock.pause')}
+          aria-label=${t('indexdock.pause')} onClick=${onPause}>
+          <${Icon} name="pause" />
+        </button>
+      `}
       ${!done && html`
         <button type="button" class="index-dock-hide" title=${t('indexdock.hide')}
           aria-label=${t('indexdock.hide')} onClick=${onHide}>
@@ -156,6 +174,7 @@ export function IndexingDock({ groups }) {
   const remote = usePushedActivity();
   const memory = useRef({});
   const [, setTick] = useState(0);
+  const [errors, setErrors] = useState({});
   // Publishes `--index-dock-h` for the sidebar, as the music bar publishes its
   // own; withdrawn when the dock renders nothing.
   const band = useStickyBand('--index-dock-h');
@@ -173,11 +192,36 @@ export function IndexingDock({ groups }) {
     return () => clearInterval(id);
   }, [pending]);
 
+  // A whole-root walk names its root; a burst of file events does not, and
+  // there is nothing to pause. The local node first, as for the figures.
+  const pauser = (row) => {
+    if (row.state !== 'running' || !row.scanning || !row.root) return null;
+    if (local[row.groupId]) {
+      return (rootName) => platform.node.op('pauseRoot', { groupId: row.groupId, rootName });
+    }
+    return pushedPause.get(row.groupId) || null;
+  };
+
+  const pause = async (row, via) => {
+    const before = memory.current;
+    memory.current = pauseRow(memory.current, row.groupId);
+    setErrors((e) => ({ ...e, [row.groupId]: '' }));
+    setTick((n) => n + 1);
+    try {
+      await via(row.root);
+    } catch (err) {
+      // Still running: put the row back, and say why.
+      memory.current = { ...memory.current, [row.groupId]: before[row.groupId] };
+      setErrors((e) => ({ ...e, [row.groupId]: platform.bridgeMessage(err) }));
+    }
+  };
+
   if (!rows.length) return null;
   return html`
     <div class="index-dock" ref=${band}>
       ${rows.map((row) => html`
-        <${DockRow} key=${row.groupId} row=${row}
+        <${DockRow} key=${row.groupId} row=${row} error=${errors[row.groupId] || ''}
+          onPause=${pauser(row) && (() => pause(row, pauser(row)))}
           onOpen=${() => {
             session.openGroupTab = { groupId: row.groupId, tab: 'settings' };
             navigate('/group/' + row.groupId);