chore(frontend): scrub pre-existing issue-tag refs from source comments

The no-issue-tags-in-code rule (knowledge/hive-rules.md) was enforced on
recent PRs but several pre-existing parenthetical refs remained in the
frontend source. Replace them with plain prose — issue numbers are opaque
in source, and prose survives repo migrations + doesn't confuse static
analysis. Comment-only; no behaviour change.

- tabs.js: 4× operator-inbox refs → prose
- flow.js / flow.css: agent-filter + sent/delivered-collapse refs → prose
- home.js / home.css: H0M3 page-script + page-chrome refs → prose
- dashboard.html: 1NB0X inbox ref → prose

Closes #1549.

frontend/packages/dashboard/src/tabs.js

@@ -3975,7 +3975,7 @@ window.marked = marked;
     }
   }
   refreshState();
-  // Cold-load the operator inbox (#1469) so the Y3R C4LL pill + browser
+  // Cold-load the operator inbox so the Y3R C4LL pill + browser
   // title reflect unread agent→operator messages immediately, before the
   // operator opens the tab. Live updates arrive via the broker stream.
   refreshOperatorInbox();
@@ -4030,7 +4030,7 @@ window.marked = marked;
       let ev;
       try { ev = JSON.parse(e.data); } catch { return; }
       // Broker `sent` frames aren't mutation events, but the operator
-      // inbox (#1469) cares about ones addressed to "operator".
+      // inbox cares about ones addressed to "operator".
       if (ev.kind === 'sent' && ev.to === 'operator') {
         operatorInboxAppendFromEvent(ev);
         return;
@@ -4201,7 +4201,7 @@ window.marked = marked;
   // stores so SSE-driven updates flow through without extra plumbing.
   // Set `hidden` when the count is zero so the pill doesn't draw
   // attention to an empty room.
-  // ─── operator inbox (#1469) — unread agent→operator messages ────────────
+  // ─── operator inbox — unread agent→operator messages ────────────
   // The Y3R C4LL tab surfaces messages agents `send(to: "operator")` so
   // the operator stops missing them. Unread = broker rows to "operator"
   // with `acked_at IS NULL`; cold-loaded from `/api/operator-inbox`,
@@ -4285,7 +4285,7 @@ window.marked = marked;
     }
     setTabCount('swarm', swarm);
     // Y3R C4LL — pending approvals + operator-targeted questions +
-    // unread agent→operator messages (#1469).
+    // unread agent→operator messages.
     const callCount =
       (approvalsState?.pending?.length ?? 0) +
       (questionsState?.pending?.length ?? 0) +