dashboard: consolidate NodeView.has_log into build_log_id

Per mara's review on #2896: has_log: bool was fully redundant once
build_log_id: Option<i64> existed alongside it (has_log was always
just build_log_id.is_some()). Dropped has_log, threading the single
Option<i64> field through job_queue::mod.rs, the hivectl NodeView
test-helper literal, and the one remaining frontend consumer
(findLiveBuild's live-log-panel gate, which now checks
build_log_id != null instead of the separate bool).

Also fixed a now-stale doc comment on GET /api/build-log/{node_id}
that claimed the dashboard used on-demand node-id fetches "instead
of an inline build_log_id on the wire" -- no longer true after this
PR put one there for the BUILD L0GS deep-link.

cargo build/clippy/test clean across the three touched crates; nix
fmt clean; frontend build verified (0 has_log references, 3
build_log_id references in the built builds.js bundle).

frontend/packages/dashboard/src/builds.js

@@ -376,12 +376,17 @@ function renderQueueEntry(entry) {
         chip.append(el('span', { class: 'rqe-node-agent' }, ' · ' + n.agent));
       }
       row.append(chip);
-      if (n.has_log) {
+      if (n.build_log_id != null) {
+        // Deep-links into the BUILD L0GS tab's rich view (auto-expands +
+        // scrolls to this row there, see fetchBuild's `?id=N` handling)
+        // rather than the raw-text download endpoint — a plain download
+        // is surprising here since nothing about a printer-glyph icon
+        // says "this leaves the app".  The raw download is still one
+        // click away once on that row.
         row.append(el('a', {
           class: 'rqe-log-link rqe-node-log',
-          href: '/api/build-log/' + n.id + '/raw',
-          target: '_blank',
-          title: 'download build log for ' + n.kind + ' node',
+          href: '/builds.html?id=' + n.build_log_id + '#buildlogs',
+          title: 'view build log for ' + n.kind + ' node',
         }, '⎙'));
       }
       treeRoot.append(row);
@@ -439,11 +444,11 @@ function clearLiveLogPoll() {
 }
 
 // First (entry, node) pair with a running node that has a log.
-// Gate on has_log so lock/noop/store-only nodes don't open a blank panel.
+// Gate on build_log_id so lock/noop/store-only nodes don't open a blank panel.
 function findLiveBuild(queue) {
   for (const e of queue || []) {
     if (rollupState(e.nodes || []) !== 'Running') continue;
-    const node = (e.nodes || []).find((n) => n.state === 'Running' && n.has_log);
+    const node = (e.nodes || []).find((n) => n.state === 'Running' && n.build_log_id != null);
     if (node) return { entry: e, node };
   }
   return null;

hive-c0re/src/dashboard/build_logs.rs

@@ -130,9 +130,11 @@ pub(super) async fn get_build_log_full(
 /// `GET /api/build-log/{node_id}` — the build log for a **queue node**,
 /// resolved node id → log-row id → full log. Same `BuildLogFull` JSON
 /// (`stdout` / `stderr` + header) as `get_build_log_full`; HTTP 404 when the
-/// node has no linked log (the client gates the request on `NodeView.has_log`,
-/// but a vacuum race can still 404). This is the on-demand log fetch the
-/// raw-graph dashboard uses instead of an inline `build_log_id` on the wire.
+/// node has no linked log (the client gates the request on
+/// `NodeView.build_log_id`, but a vacuum race can still 404). This is the
+/// on-demand live-log-panel fetch, distinct from the `build_log_id` on the
+/// wire — that id is for deep-linking to the BUILD L0GS tab's full history
+/// view, not for fetching the log content itself.
 #[utoipa::path(
     get,
     path = "/api/build-log/{node_id}",

hive-c0re/src/job_queue/mod.rs

@@ -559,7 +559,7 @@ impl QueueInner {
             } else {
                 Vec::new()
             };
-            let has_log = self.node_rt.get(&id).and_then(|r| r.build_log_id).is_some();
+            let build_log_id = self.node_rt.get(&id).and_then(|r| r.build_log_id);
             // `node.parent` is the structural jobq parent. Top-level nodes
             // have `parent == Some(container)` (direct children of the Dag
             // container); those become `parent: None` on the wire since the
@@ -580,7 +580,7 @@ impl QueueInner {
                 error: node.error.clone(),
                 approval_id,
                 inputs,
-                has_log,
+                build_log_id,
                 parent,
             });
         }

hive-host-sock/src/jobs.rs

@@ -105,12 +105,14 @@ pub struct NodeView {
     /// node. Display-only payload, not derivable from the graph.
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub inputs: Vec<String>,
-    /// Whether this node has a captured build log fetchable at
-    /// `GET /api/build-log/<id>`. Only the nix-heavy nodes that stream build
-    /// output set one; the client gates its log link on this so lock / noop /
-    /// store-only nodes don't render a link that 404s.
-    #[serde(default)]
-    pub has_log: bool,
+    /// The build-log history row id, when this node has a captured build
+    /// log fetchable at `GET /api/build-log/<node id>` and deep-linkable to
+    /// `/builds.html?id=<this>#buildlogs`. Only the nix-heavy nodes that
+    /// stream build output set one; the client gates its log link on
+    /// `.is_some()` so lock / noop / store-only nodes don't render a link
+    /// that 404s.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub build_log_id: Option<i64>,
     /// Structural parent in the jobq tree — `None` for top-level nodes
     /// (direct children of the DAG container). Sub-nodes carry the id of
     /// their containing parent node. The client uses this to render the

hivectl/src/dag_progress.rs

@@ -342,7 +342,7 @@ mod tests {
             error: None,
             approval_id: None,
             inputs: vec![],
-            has_log: false,
+            build_log_id: None,
         }
     }