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.

docs/web-ui/dashboard.md

@@ -11,7 +11,7 @@ matrix accounts, the controller's job graph — are on the
 hive-c0re serves the dashboard at `/`.
 It has a fixed chrome header at the top and a `<main>` that shows exactly
 one tab pane at a time. The URL hash (`#agents`, `#rebuild`, `#meta`,
-`#buildlogs`, `#kept`) drives which pane is
+`#kept`) drives which pane is
 active; hash changes don't reload the page. ST4TS
 is a standalone page reached from the pages menu, not from the
 dashboard tab strip.
@@ -35,10 +35,8 @@ dashboard tab strip.
   If the name doesn't load the avatar shows a question mark, and without the URL the
   popover has no links.
 - **Tab strip**: `◆ 4G3NTS ◆`, `◆ R3BU1LD QU3U3 ◆`,
-  `◆ BUILD L0GS ◆`, `◆ K3PT ST4T3 ◆`. In-page tabs only — ST4TS
-  lives on its own page, reached from the pages menu. Count pills on
-  4G3NTS (stale containers), R3BU1LD QU3U3 (rebuilds in flight) and
-  K3PT ST4T3 (kept-state entries).
+  `◆ K3PT ST4T3 ◆`. In-page tabs only — ST4TS
+  lives on its own page, reached from the pages menu.
 - **Banner-thin** (`░▒▓█▓▒░ HYPERHIVE / HIVE-C0RE / WE ARE THE WIRED ░▒▓█▓▒░`)
   — sits below the tab strip.
 - **No warning banner.** No page shows hive-level warnings (host disk
@@ -97,12 +95,9 @@ container is all hive-c0re can actually prove. Fixing it properly
 needs a recorded destroy — **deferred** to the swarm-controller /
 snapshot-storage rework where the problem changes shape.
 
-## Build tabs (`#rebuild`, `#buildlogs`)
+## Build tab (`#rebuild`)
 
-The build lifecycle — rebuild queue, live build log, and
-build log history — is two tabs of the dashboard: **R3BU1LD QU3U3**
-(`#rebuild`) and **BUILD L0GS**
-(`#buildlogs`). They live in `builds.js`, which `tabs.js` imports: the
+The rebuild queue is the **R3BU1LD QU3U3** tab (`#rebuild`). It lives in `builds.js`, which `tabs.js` imports: the
 dashboard's one tab strip, `/api/state` snapshot and
 `/api/dashboard/stream` subscription serve them, with
 `rebuild_queue_changed` on the stream alongside the dashboard's other
@@ -156,7 +151,7 @@ the tree — one per lifecycle state, matching the row glyphs — lets the
 operator narrow which root groups render; unchecking a state re-fetches
 `GET /api/jobq/graph?states=<checked, comma-joined>` rather than
 hiding rows client-side, so the `onUpdate` callback's node list (and
-everything downstream of it — the live-log panel) only
+everything downstream of it) only
 ever sees what's actually shown. Filtering is by a **root's own**
 state, which is already its subtree's rolled-up answer, so the filter
 keeps or drops a whole group, never splitting mid-tree. Default selection is
@@ -169,34 +164,9 @@ root set — the history cap and the state filter are independent
 concerns, so a narrow filter never reaches further back in time to
 compensate.
 
-Below the queue, a **live build-log panel** (`#rebuild-live-log`,
-`renderRebuildLiveLog`) shows the currently running rebuild's output
-inline — collapsible, with a live/ok/fail badge and a `↓ raw`
-download. It's keyed to the first `Running` node (in wire order)
-whose `payload.data.build_log_id` has a value — read from the `onUpdate`
-callback's node list, no separate
-fetch — and **polls** `GET /api/build-log/{id}` every 2s
-(`fetchAndRenderLiveLog` / `liveLogPollTimer`); not an `EventSource`
-(that's the BUILD L0GS tab's own per-row expand view below — `GET
-/api/build-logs/id/{id}/stream`, real SSE, replays accumulated output
-on connect — a separate mechanism). The live-log panel lives in its
-own container outside `#rebuild-queue-section` so the mounted
-`JobqGraph`'s own re-renders never disturb the open poll; it hides
-when nothing is building.
-
-
-**BUILD L0GS** — all-agents build log history. Lazy-loaded on first tab
-activation; autorefreshes when
-`rebuild_queue_changed` fires. Fetches `GET /api/build-logs?limit=30`.
-Renders a scrollable list of build entries; each row is a collapsible
-button showing status badge (`live` / `ok` / `fail`), agent name,
-elapsed duration, build kind, age, and the invocation command line.
-Expanding a row fetches the full stdout+stderr via
-`GET /api/build-logs/id/{id}`. A live in-progress build shows a `live`
-badge with a ticking elapsed-time chip; expanding streams output via
-`GET /api/build-logs/id/{id}/stream` with sticky-bottom autoscroll
-(suspends on manual scroll-up). Deep-link: `?id=N#buildlogs` opens the
-entry with that id pre-expanded.
+A build's output and history aren't on this page. hive-c0re logs every container build
+to the journal, and the swarm's `builds` Grafana board reads those lines: the builds with
+their outcome and runtime, and the output of the one you pick.
 
 ## ST4TS page (`/stats.html`)
 
@@ -544,11 +514,10 @@ below — some endpoints aren't in it yet.
   404 when the row is missing (vacuum-reaped or stale id).
 - `GET /api/build-logs/id/{id}/stream` — live SSE stream of
   stdout+stderr for an in-progress build (newline-delimited JSON
-  frames). Used by the expanding live-row view in the BUILD L0GS tab. The
+  frames). The
   stream closes when the build finishes or errors.
 - `GET /api/build-logs/id/{id}/raw` — raw concatenated
-  stdout+stderr as `text/plain`. Used by the `↓ raw` / `↓ download
-  raw` links in the build tabs. Works on both finished and in-progress
+  stdout+stderr as `text/plain`. Works on both finished and in-progress
   build logs.
 - `GET /api/reminders` — list pending reminders for the
   dashboard's queued-reminders panel.