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/flow.js

@@ -36,7 +36,7 @@ import {
     populateAgentFilter();
   }).catch(() => { /* graceful: compose just shows `*` and nothing else */ });
 
-  // ─── agent filter (#1473) ───────────────────────────────────────────────
+  // ─── agent filter ───────────────────────────────────────────────
   // A select in the FL0W header narrows the timeline to messages involving
   // one agent (matched on `from` OR `to`). Each rendered row carries
   // `data-from` / `data-to`; non-matching rows get `.flow-hidden`. New rows
@@ -158,7 +158,7 @@ import {
       } else {
         row.append(ts, ' ', arrow, ' ', from, ' ', sep, ' ', to, ' ', body);
       }
-      // Tag with the participants so the agent filter (#1473) can match
+      // Tag with the participants so the agent filter can match
       // on `from`/`to`, and hide the row up-front if a filter is active.
       row.dataset.from = ev.from;
       row.dataset.to = ev.to;
@@ -168,7 +168,7 @@ import {
       return row;
     }
 
-    // Sent→Delivered collapse (#1472). When a message directly wakes its
+    // Sent→Delivered collapse. When a message directly wakes its
     // recipient the broker emits `sent` then `delivered` for the same row
     // id back-to-back, rendering two near-identical lines. We track each
     // recent `sent` row and, when its `delivered` lands within