dashboard: tombstones + meta_inputs events — last /api/state refetches drop

new DashboardEvent::TombstonesChanged + MetaInputsChanged carry
full snapshots (lists are tiny; snapshot beats diff for race
avoidance). Coordinator-side helpers
emit_tombstones_snapshot + emit_meta_inputs_snapshot fire from
every mutation site: actions::destroy + post_purge_tombstone +
actions::approve (spawn finalise consumes tombstone) +
run_meta_update + auto_update::rebuild_agent (lock bumps).

client adds derived stores + apply* handlers + drops the
post-submit refetch on PURG3 (container row + tombstone row)
and meta-update.

after this commit /api/state is fetched exactly once per page
session (cold load); every other change rides the SSE channel.

hive-c0re/assets/app.js

@@ -335,6 +335,32 @@
     if (containersState.delete(ev.name)) renderContainersFromState();
   }
 
+  // Derived tombstones + meta_inputs. Both are emitted as full
+  // snapshots (not diffs) — the lists are tiny and recomputing
+  // avoids ordering races between a same-tick destroy + purge.
+  let tombstonesState = [];
+  let metaInputsState = [];
+  function syncTombstonesFromSnapshot(s) {
+    tombstonesState = (s.tombstones || []).slice();
+  }
+  function syncMetaInputsFromSnapshot(s) {
+    metaInputsState = (s.meta_inputs || []).slice();
+  }
+  function applyTombstonesChanged(ev) {
+    tombstonesState = (ev.tombstones || []).slice();
+    renderTombstonesFromState();
+  }
+  function applyMetaInputsChanged(ev) {
+    metaInputsState = (ev.inputs || []).slice();
+    renderMetaInputsFromState();
+  }
+  function renderTombstonesFromState() {
+    renderTombstones({ tombstones: tombstonesState });
+  }
+  function renderMetaInputsFromState() {
+    renderMetaInputs({ meta_inputs: metaInputsState });
+  }
+
   // Derived transient state — cold-loaded from /api/state.transients,
   // then mutated live by `transient_set` / `transient_cleared`. Keyed
   // by agent name so add/remove are O(1). `since_unix` is wall-clock so
@@ -512,14 +538,16 @@
       if (!c.is_manager) {
         // DESTR0Y is event-covered (ContainerRemoved); PURG3 also
         // wipes tombstone state which isn't event-derived yet, so it
-        // keeps the post-submit refetch.
+        // Both event-covered now (ContainerRemoved +
+        // TombstonesChanged); no /api/state refetch needed.
         actions.append(
           form('/destroy/' + c.name, 'btn-destroy', 'DESTR0Y',
             'destroy ' + c.name + '? container is removed; state + creds kept.',
             {}, { noRefresh: true }),
           form('/destroy/' + c.name, 'btn-destroy', 'PURG3',
             'PURGE ' + c.name + '? container, config history, claude creds, '
-            + 'and notes are all WIPED. no undo.', { purge: 'on' }),
+            + 'and notes are all WIPED. no undo.',
+            { purge: 'on' }, { noRefresh: true }),
         );
       }
       li.append(actions);
@@ -683,8 +711,9 @@
       actions.append(respawn);
       actions.append(form(
         '/purge-tombstone/' + t.name, 'btn-destroy', 'PURG3',
-        'PURGE ' + t.name + '? config history, claude creds, /state/ notes '
-        + 'are all WIPED. no undo.',
+        'PURGE ' + t.name + '? config history, claude creds, '
+        + 'and notes are all WIPED. no undo.',
+        {}, { noRefresh: true },
       ));
       li.append(actions);
       ul.append(li);
@@ -1214,6 +1243,10 @@
       action: '/meta-update',
       class: 'meta-inputs-form',
       'data-async': '',
+      // run_meta_update emits MetaInputsChanged once the lock
+      // bump finishes; per-agent rebuilds fire their own
+      // ContainerStateChanged. No /api/state refetch needed.
+      'data-no-refresh': '',
       'data-confirm': 'update selected meta flake inputs + rebuild affected agents?',
     });
     const ul = el('ul', { class: 'meta-inputs' });
@@ -1419,6 +1452,8 @@
       // `transientsState` + `containersState`, not from `s.*`).
       syncTransientsFromSnapshot(s);
       syncContainersFromSnapshot(s);
+      syncTombstonesFromSnapshot(s);
+      syncMetaInputsFromSnapshot(s);
       renderContainers(s);
       renderTombstones(s);
       // Sync the derived approvals + questions stores from the
@@ -1513,6 +1548,8 @@
         transient_cleared: (ev) => { applyTransientCleared(ev); },
         container_state_changed: (ev) => { applyContainerStateChanged(ev); },
         container_removed:       (ev) => { applyContainerRemoved(ev); },
+        tombstones_changed:      (ev) => { applyTombstonesChanged(ev); },
+        meta_inputs_changed:     (ev) => { applyMetaInputsChanged(ev); },
       },
       // Both history backfill and live frames flow through here, so the
       // inbox section ends up populated correctly on first paint and