hive ui: remove the BUILD L0GS tab and the live build-log panel

A build's output and history are the swarm's builds Grafana board now, from the
lines hive-c0re logs. Removes the tab and its pane, the live log under the
rebuild queue, their styles, the log stream helper and the duration formatter
only they used, and the docs; also the tab-counts sentence 5925 missed.

frontend/packages/dashboard/src/index.html

@@ -42,16 +42,6 @@
           <span class="tab-label">◆ R3BU1LD QU3U3 ◆</span>
         </a>
 
-        <a
-          class="tab"
-          id="tab-buildlogs"
-          href="#buildlogs"
-          role="tab"
-          aria-controls="tab-pane-buildlogs"
-          data-tab="buildlogs"
-        >
-          <span class="tab-label">◆ BUILD L0GS ◆</span>
-        </a>
         <a
           class="tab"
           id="tab-kept"
@@ -137,35 +127,6 @@
           <div id="rebuild-queue-section">
             <p class="meta">loading…</p>
           </div>
-          <!-- Live build log of the currently-running rebuild (one runs at a
-           time). Managed by renderRebuildLiveLog in builds.js, separate from
-           rebuild-queue-section so the queue's row re-render never disturbs
-           the open poll. -->
-          <div id="rebuild-live-log" class="rebuild-live-log" hidden></div>
-        </section>
-
-        <!-- BUILD L0GS: all-agents build log history. Click a row to expand
-         stdout + stderr. Live builds stream in real time. Lazy-loaded the
-         first time the tab is shown; auto-refreshes when
-         rebuild_queue_changed fires. Deep-link: ?id=N#buildlogs. -->
-        <section
-          class="tab-pane"
-          id="tab-pane-buildlogs"
-          data-tab-pane="buildlogs"
-          hidden
-          role="tabpanel"
-          aria-labelledby="tab-buildlogs"
-        >
-          <p class="meta">
-            all-agents build log history. click a row to expand stdout + stderr.
-            live builds stream in real time.
-          </p>
-          <div class="logs-toolbar">
-            <button type="button" class="btn btn-restart" id="build-refresh">
-              ↻ refresh
-            </button>
-          </div>
-          <div id="build-list"><p class="meta">loading…</p></div>
         </section>
 
         <!-- K3PT ST4T3: kept state from agents whose container is absent,