loops: per-iteration live logs (Steps + Container tabs), collapse graph JSON

The Loops canvas' IterationsTimeline was a flat status-pill list —
no way to see WHAT an iteration was actually doing. Meanwhile the
Research canvas had full LiveRunLogs with Steps + Container tabs
against the same underlying topology_run SSE endpoints. This
factors LiveRunLogs so both canvases share it.

Frontend
- LiveRunLogs gains a directRunId?: string prop. In this mode it
  skips the topic-scoped active-runs + pipeline-state polls and
  pins activeRun to the given id. topicId stays optional (topic
  mode unchanged from ResearchCanvas' perspective).
- LoopsCanvas IterationsTimeline: each row is now a click-to-
  expand card. On expand, renders <LiveRunLogs directRunId={...}/>
  right below the header — Steps + Container tabs, full SSE tail,
  same 320px terminal.
- Auto-opens the newest running/queued iteration so a click on
  'Run now' immediately exposes the live pane.
- New CollapsibleSection helper wraps the graph JSON block so it
  starts closed. Reference material stays one click away without
  cluttering the canvas.

Backend
- run_container_log_sse now resolves the tail target via
  loop.source_research_topic_id when the run itself has no
  research_topic_id. Paired coding loops (kind=exec with a
  source_research_topic_id) reuse the paired topic's team
  container, so we tail its docker logs. Pure loop runs still
  error with a clearer message.

crates/cm-api/src/routes/topology.rs

@@ -482,22 +482,47 @@ pub async fn run_container_log_sse(
     let ws = user.workspace_id;
     let stream = async_stream::stream! {
         use futures::StreamExt;
-        // 1) Workspace scope + topic id.
-        let topic_id = match cm_db::repo::topology_runs::status(&pool, id, ws).await {
-            Ok(_) => match cm_db::repo::topology_runs::research_topic_id(&pool, id).await {
-                Ok(Some(t)) => t,
-                _ => {
-                    yield Ok::<Event, Infallible>(
-                        Event::default().event("error").data(
-                            "run has no bound research topic; container log unavailable",
-                        ),
-                    );
-                    return;
+        // 1) Workspace scope + resolve the topic id whose container we'll
+        //    tail. Two paths:
+        //      a) run.research_topic_id set → research pipeline; use it
+        //         directly (existing behavior).
+        //      b) research_topic_id NULL + run belongs to a loop whose
+        //         source_research_topic_id is set → paired coding loop;
+        //         the loop reuses the research topic's team container.
+        //    Anything else (raw topology runs, pure loop with no paired
+        //    topic) errors out with a clear message.
+        if cm_db::repo::topology_runs::status(&pool, id, ws).await.is_err() {
+            yield Ok::<Event, Infallible>(
+                Event::default().event("error").data("run not found"),
+            );
+            return;
+        }
+        let direct = cm_db::repo::topology_runs::research_topic_id(&pool, id).await.ok().flatten();
+        let via_loop = if direct.is_none() {
+            let loop_id = cm_db::repo::topology_runs::loop_id_for_run(&pool, id).await.ok().flatten();
+            match loop_id {
+                Some(lid) => {
+                    use sqlx::Row;
+                    sqlx::query(
+                        "SELECT source_research_topic_id FROM loops WHERE id = $1"
+                    )
+                        .bind(lid)
+                        .fetch_optional(&pool)
+                        .await
+                        .ok()
+                        .flatten()
+                        .and_then(|r| r.try_get::<Option<Uuid>, _>("source_research_topic_id").ok().flatten())
                 }
-            },
-            Err(_) => {
+                None => None,
+            }
+        } else { None };
+        let topic_id = match direct.or(via_loop) {
+            Some(t) => t,
+            None => {
                 yield Ok::<Event, Infallible>(
-                    Event::default().event("error").data("run not found"),
+                    Event::default().event("error").data(
+                        "run has no bound research topic or paired-loop topic; container log unavailable",
+                    ),
                 );
                 return;
             }