feat: show transport badge in live packet feed (#551)

## Summary

Show the transport badge ("T") in the live packet feed, matching the
packets table (#337).

## Changes

- Add `transportBadge(pkt.route_type)` to all 4 feed rendering paths in
`live.js`:
  - Grouped feed items (initial history load)
  - `addFeedItemDOM()` (VCR replay)
  - Dedup new feed items (live WebSocket updates)
  - Node detail panel recent packets list
- Uses existing `transportBadge()` from `app.js` and `.badge-transport`
CSS from `style.css`

## Testing

- 2 new source-level assertions in `test-live.js` verifying
`transportBadge()` calls exist
- All existing tests pass (67 passed in test-live.js, no new failures)

Fixes #338

Co-authored-by: you <you@example.com>

public/live.js

@@ -1343,7 +1343,7 @@
         html += `<h4 style="font-size:12px;margin:12px 0 6px;color:var(--text-muted);">Recent Packets</h4>
           <div style="font-size:11px;max-height:200px;overflow-y:auto;">` +
           recent.slice(0, 10).map(p => `<div style="padding:2px 0;display:flex;justify-content:space-between;">
-            <a href="#/packets/${encodeURIComponent(p.hash || '')}" style="color:var(--accent);text-decoration:none;">${escapeHtml(p.payload_type || '?')}${p.observation_count > 1 ? ' <span class="badge badge-obs" style="font-size:9px">👁 ' + p.observation_count + '</span>' : ''}</a>
+            <a href="#/packets/${encodeURIComponent(p.hash || '')}" style="color:var(--accent);text-decoration:none;">${escapeHtml(p.payload_type || '?')}${transportBadge(p.route_type)}${p.observation_count > 1 ? ' <span class="badge badge-obs" style="font-size:9px">👁 ' + p.observation_count + '</span>' : ''}</a>
             <span style="color:var(--text-muted)">${formatLiveTimestampHtml(p.timestamp)}</span>
           </div>`).join('') +
           '</div>';
@@ -1548,7 +1548,7 @@
       item.innerHTML = `
         <span class="feed-icon" style="color:${color}">${icon}</span>
         <span class="feed-type" style="color:${color}">${typeName}</span>
-        ${hopStr}${obsBadge}
+        ${transportBadge(pkt.route_type)}${hopStr}${obsBadge}
         <span class="feed-text">${escapeHtml(preview)}</span>
         <span class="feed-time">${formatLiveTimestampHtml(group.latestTs || Date.now())}</span>
       `;
@@ -2490,7 +2490,7 @@
     item.innerHTML = `
       <span class="feed-icon" style="color:${color}">${icon}</span>
       <span class="feed-type" style="color:${color}">${typeName}</span>
-      ${hopStr}${obsBadge}
+      ${transportBadge(pkt.route_type)}${hopStr}${obsBadge}
       <span class="feed-text">${escapeHtml(preview)}</span>
       <span class="feed-time">${formatLiveTimestampHtml(pkt._ts || Date.now())}</span>
     `;
@@ -2558,7 +2558,7 @@
     item.innerHTML = `
       <span class="feed-icon" style="color:${color}">${icon}</span>
       <span class="feed-type" style="color:${color}">${typeName}</span>
-      ${hopStr}${obsBadge}
+      ${transportBadge(pkt.route_type)}${hopStr}${obsBadge}
       <span class="feed-text">${escapeHtml(preview)}</span>
       <span class="feed-time">${formatLiveTimestampHtml(pkt._ts || Date.now())}</span>
     `;

test-live.js

@@ -881,6 +881,17 @@ console.log('\n=== live.js: source-level safety checks ===');
     assert.ok(src.includes('const existingIds = new Set(VCR.buffer.map(b => b.pkt.id)'),
       'vcrRewind should dedup by packet ID');
   });
+
+  test('feed items include transport badge', () => {
+    const count = (src.match(/transportBadge\(pkt\.route_type\)/g) || []).length;
+    assert.ok(count >= 3,
+      `feed rendering should call transportBadge(pkt.route_type) in at least 3 places (found ${count})`);
+  });
+
+  test('node detail recent packets include transport badge', () => {
+    assert.ok(src.includes('transportBadge(p.route_type)'),
+      'node detail recent packets should call transportBadge(p.route_type)');
+  });
 }
 
 // ===== SUMMARY =====