diff --git a/crates/worker/src/worker.rs b/crates/worker/src/worker.rs
index 18c440419..6b91903ea 100644
--- a/crates/worker/src/worker.rs
+++ b/crates/worker/src/worker.rs
@@ -5291,6 +5291,10 @@ impl<C: LlmClient + 'static, St: Store> Worker<C, St> {
                 info!(new_segment_id = %new_segment_id, "Manual compaction succeeded");
                 Ok(ManualCompactResult::Compacted { new_segment_id })
             }
+            Err(WorkerError::CompactCancelled) => {
+                info!("Manual compaction was cancelled");
+                Err(WorkerError::CompactCancelled)
+            }
             Err(e) => {
                 warn!(error = %e, "Manual compaction failed");
                 self.alert(
diff --git a/crates/worker/tests/compact_events_test.rs b/crates/worker/tests/compact_events_test.rs
index 68842c5c9..2c71f3e46 100644
--- a/crates/worker/tests/compact_events_test.rs
+++ b/crates/worker/tests/compact_events_test.rs
@@ -1736,7 +1736,11 @@ async fn manual_compact_cancel_clears_progress_before_returning_idle() {
             Event::CompactionProgress { compaction: None } => {
                 saw_interrupted = true;
             }
-            Event::Error { .. } => saw_cancel_error = true,
+            Event::Error { .. }
+            | Event::Alert(protocol::Alert {
+                level: protocol::AlertLevel::Error,
+                ..
+            }) => saw_cancel_error = true,
             Event::WorkerState { snapshot }
                 if snapshot.catalog_status() == protocol::WorkerStatus::Idle =>
             {
diff --git a/web/workspace/src/lib/workspace/console/model.test.ts b/web/workspace/src/lib/workspace/console/model.test.ts
index b831db902..adaa5c669 100644
--- a/web/workspace/src/lib/workspace/console/model.test.ts
+++ b/web/workspace/src/lib/workspace/console/model.test.ts
@@ -376,6 +376,35 @@ Deno.test("durable compaction failure reconciles live alert and error in both vi
   assertEquals(merged.find((line) => line.kind === "error")?.entryId, "failed-entry");
 });
 
+Deno.test("reapplying one committed run_error entry is idempotent in both views", () => {
+  const committed = (eventId: string): ConsoleEventInput => ({
+    eventId,
+    event: {
+      event: "session_entry_committed",
+      data: {
+        entry: {
+          entry_id: "same-run-error",
+          timestamp: 10,
+          provenance: "legacy_unknown",
+          kind: "run_error",
+          message: "mid-run compaction failed: summary unavailable",
+          failure: "compaction",
+        },
+      },
+    },
+  });
+
+  const projection = projectConsole([
+    committed("live-delivery"),
+    committed("snapshot-replay"),
+  ]);
+  const errors = projection.lines.filter((line) => line.kind === "error");
+  assertEquals(errors.length, 1);
+  assertEquals(errors[0].entryId, "same-run-error");
+  assertEquals(projectConsoleLines(projection.lines, "normal").length, 1);
+  assertEquals(projectConsoleLines(projection.lines, "overview").length, 1);
+});
+
 Deno.test("snapshot restores compaction terminal without reviving transition progress", () => {
   const projection = projectConsole([{
     eventId: "snapshot",
diff --git a/web/workspace/src/lib/workspace/console/model.ts b/web/workspace/src/lib/workspace/console/model.ts
index 1471417aa..cdfca96d2 100644
--- a/web/workspace/src/lib/workspace/console/model.ts
+++ b/web/workspace/src/lib/workspace/console/model.ts
@@ -1287,15 +1287,19 @@ function hasDurableRunFailure(
 function appendDurableRunFailure(
   projection: ConsoleProjection,
   eventId: string,
+  entryId: string | undefined,
   message: string,
   failure: string | undefined,
 ): void {
+  if (
+    entryId && projection.lines.some((line) => line.entryId === entryId)
+  ) return;
   projection.lines = projection.lines.filter((line) => {
     if (isDurableRunFailure(line)) return true;
     return !(line.kind === "error" && runFailureMessagesMatch(line.body, message));
   });
-  projection.lines.push(
-    line(
+  projection.lines.push({
+    ...line(
       eventId,
       "error",
       failure === "compaction" ? "Compaction failed" : "Run error",
@@ -1304,7 +1308,8 @@ function appendDurableRunFailure(
       false,
       true,
     ),
-  );
+    entryId,
+  });
 }
 
 function appendAlertLine(
@@ -2198,6 +2203,7 @@ function applySessionEntry(
       appendDurableRunFailure(
         projection,
         eventId,
+        stringField(value, "entry_id"),
         stringField(value, "message") ?? "Worker run failed.",
         stringField(value, "failure"),
       );