diff --git a/scripts/src/hwlab-node-web-observe-analyzer-source.ts b/scripts/src/hwlab-node-web-observe-analyzer-source.ts
index 98e6c309..979ac3b0 100644
--- a/scripts/src/hwlab-node-web-observe-analyzer-source.ts
+++ b/scripts/src/hwlab-node-web-observe-analyzer-source.ts
@@ -2467,11 +2467,15 @@ function detectWorkbenchTerminalApiDomLag(samples, network) {
   for (const event of terminalEvents) {
     const pageSamples = rowsByPage.get(event.pageKey) || [];
     if (pageSamples.length === 0 || event.tsMs < pageSamples[0].tsMs) continue;
+    const alreadyVisible = lastWorkbenchSampleAtOrBefore(pageSamples, event.tsMs, event, (row) => workbenchSampleHasTerminalProjection(row.sample, event));
+    if (alreadyVisible) continue;
     const firstAfter = firstWorkbenchSampleAfter(pageSamples, event.tsMs, event.tsMs + windowMs, event);
+    const firstMiss = firstWorkbenchSampleAfter(pageSamples, event.tsMs, event.tsMs + budgetMs, event, (row) => !workbenchSampleHasTerminalProjection(row.sample, event));
     const resolved = firstWorkbenchSampleAfter(pageSamples, event.tsMs, event.tsMs + windowMs, event, (row) => workbenchSampleHasTerminalProjection(row.sample, event));
     const deltaMs = resolved ? Math.max(0, Math.round(resolved.tsMs - event.tsMs)) : null;
     const unresolved = !resolved;
     const exceedsBudget = unresolved || (Number.isFinite(deltaMs) && deltaMs > budgetMs);
+    if (!firstMiss) continue;
     if (!exceedsBudget) continue;
     overBudget.push({
       ts: event.ts,
@@ -2490,6 +2494,7 @@ function detectWorkbenchTerminalApiDomLag(samples, network) {
       resolvedDeltaMs: deltaMs,
       unresolvedWithinWindow: unresolved,
       firstAfterSample: compactWorkbenchProjectionSample(firstAfter?.sample, event),
+      firstMissSample: compactWorkbenchProjectionSample(firstMiss?.sample, event),
       resolvedSample: compactWorkbenchProjectionSample(resolved?.sample, event),
       valuesRedacted: true
     });
@@ -2547,6 +2552,17 @@ function isReliableWorkbenchTerminalApiEvent(summary, routeKind) {
   return Number(summary.runningStatusCount ?? 0) <= 0;
 }
 
+function lastWorkbenchSampleAtOrBefore(rows, tsMs, event, predicate = null) {
+  let result = null;
+  for (const row of rows || []) {
+    if (row.tsMs > tsMs) break;
+    if (!workbenchSampleMatchesTerminalEvent(row.sample, event)) continue;
+    if (typeof predicate === "function" && !predicate(row)) continue;
+    result = row;
+  }
+  return result;
+}
+
 function firstWorkbenchSampleAfter(rows, startMs, endMs, event, predicate = null) {
   for (const row of rows || []) {
     if (row.tsMs < startMs) continue;
diff --git a/scripts/src/hwlab-node-web-observe-runner-source.ts b/scripts/src/hwlab-node-web-observe-runner-source.ts
index ee43aa2e..f0c1abda 100644
--- a/scripts/src/hwlab-node-web-observe-runner-source.ts
+++ b/scripts/src/hwlab-node-web-observe-runner-source.ts
@@ -324,9 +324,16 @@ async function drainOneCommand() {
 
 function startCommandActiveSampler(command) {
   const intervalMs = Math.max(1000, Number(sampleIntervalMs) || 5000);
+  const heartbeatIntervalMs = Math.min(5000, intervalMs);
   let stopped = false;
   let timer = null;
+  let heartbeatTimer = null;
   let inFlight = false;
+  const heartbeat = () => {
+    if (stopped) return;
+    void writeHeartbeat({ status: terminalStatus, activeCommandId: command.id, activeCommandType: command.type, commandActive: true })
+      .catch((error) => appendJsonl(files.errors, eventRecord("command-active-heartbeat-error", { commandId: command.id, commandType: command.type, error: errorSummary(error) })));
+  };
   const schedule = () => {
     if (stopped) return;
     timer = setTimeout(tick, intervalMs);
@@ -346,10 +353,13 @@ function startCommandActiveSampler(command) {
         schedule();
       });
   };
+  heartbeatTimer = setInterval(heartbeat, heartbeatIntervalMs);
+  if (heartbeatTimer && typeof heartbeatTimer.unref === "function") heartbeatTimer.unref();
   schedule();
   return () => {
     stopped = true;
     if (timer) clearTimeout(timer);
+    if (heartbeatTimer) clearInterval(heartbeatTimer);
   };
 }
 
@@ -1605,7 +1615,7 @@ async function sendPrompt(text, options = {}) {
   const editor = await primaryEditor.isVisible().catch(() => false)
     ? primaryEditor
     : page.locator('textarea, [role="textbox"], [contenteditable="true"], input[type="text"]').last();
-  await editor.waitFor({ state: "visible", timeout: 15000 });
+  await withHardTimeout(editor.waitFor({ state: "visible", timeout: 15000 }), 20000, "sendPrompt composer editor did not become visible within 20s");
   await fillComposerEditor(editor, text);
   const primarySubmitSelector = '#command-send, #command-submit, [data-testid="command-submit"], [data-testid="composer-submit"], [data-testid="send-command"]';
   const primarySubmit = page.locator(primarySubmitSelector).last();
@@ -1619,7 +1629,7 @@ async function sendPrompt(text, options = {}) {
     '[aria-label*="send" i]',
     '[aria-label*="发送"]'
   ].join(", ")).last();
-  await submit.waitFor({ state: "visible", timeout: 15000 });
+  await withHardTimeout(submit.waitFor({ state: "visible", timeout: 15000 }), 20000, "sendPrompt submit button did not become visible within 20s");
   if (options.expectedAction) {
     const configuredActionWaitMs = options.expectedActionWaitMs === null || options.expectedActionWaitMs === undefined || options.expectedActionWaitMs === ""
       ? null
@@ -4405,5 +4415,18 @@ function errorSummary(error) {
 function sleep(ms) {
   return new Promise((resolve) => setTimeout(resolve, Math.max(0, ms)));
 }
+
+function withHardTimeout(promise, timeoutMs, message) {
+  const guarded = Promise.resolve(promise);
+  let timer = null;
+  const timeout = new Promise((_, reject) => {
+    timer = setTimeout(() => reject(new Error(message)), Math.max(1, Number(timeoutMs) || 1));
+    if (timer && typeof timer.unref === "function") timer.unref();
+  });
+  return Promise.race([guarded, timeout]).finally(() => {
+    if (timer) clearTimeout(timer);
+    guarded.catch(() => {});
+  });
+}
 `;
 }