diff --git a/scripts/src/hwlab-node-impl.ts b/scripts/src/hwlab-node-impl.ts
index 373aa6ec..8dca2028 100644
--- a/scripts/src/hwlab-node-impl.ts
+++ b/scripts/src/hwlab-node-impl.ts
@@ -8731,15 +8731,16 @@ function renderWebObserveAnalyzeTable(value: Record<string, unknown>): string {
   const pagePerformance = record(analysis?.pagePerformance);
   const pagePerformanceSummary = record(pagePerformance?.summary);
   const alertThresholds = record(analysis?.alertThresholds ?? pagePerformanceSummary?.alertThresholds ?? value.alertThresholds);
-  const budgetLabel = (rawValue: unknown, fallbackMs: number): string => {
+  const budgetLabel = (rawValue: unknown): string => {
     const parsed = Number(rawValue);
-    const ms = Number.isFinite(parsed) && parsed > 0 ? parsed : fallbackMs;
+    if (!Number.isFinite(parsed) || parsed <= 0) return "unconfigured";
+    const ms = parsed;
     return ms % 1000 === 0 ? `${Math.round(ms / 1000)}s` : `${ms}ms`;
   };
-  const sameOriginApiBudgetLabel = budgetLabel(alertThresholds?.sameOriginApiSlowMs ?? pagePerformanceSummary?.budgetMs, 10000);
-  const partialApiBudgetLabel = budgetLabel(alertThresholds?.partialApiSlowMs, 10000);
-  const streamOpenBudgetLabel = budgetLabel(alertThresholds?.longLivedStreamOpenSlowMs, 10000);
-  const loadingBudgetLabel = budgetLabel(alertThresholds?.visibleLoadingSlowMs, 10000);
+  const sameOriginApiBudgetLabel = budgetLabel(alertThresholds?.sameOriginApiSlowMs ?? pagePerformanceSummary?.budgetMs);
+  const partialApiBudgetLabel = budgetLabel(alertThresholds?.partialApiSlowMs);
+  const streamOpenBudgetLabel = budgetLabel(alertThresholds?.longLivedStreamOpenSlowMs);
+  const loadingBudgetLabel = budgetLabel(alertThresholds?.visibleLoadingSlowMs);
   const promptNetwork = record(analysis?.promptNetwork);
   const loading = record(sampleMetrics?.loading);
   const loadingSummary = record(loading?.summary);
diff --git a/scripts/src/hwlab-node-web-observe-runner-source.ts b/scripts/src/hwlab-node-web-observe-runner-source.ts
index 20b1f76d..e2f5fdf2 100644
--- a/scripts/src/hwlab-node-web-observe-runner-source.ts
+++ b/scripts/src/hwlab-node-web-observe-runner-source.ts
@@ -1881,27 +1881,33 @@ function positiveNumber(value, fallback) {
   return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
 }
 
+function requiredPositiveThreshold(raw, key) {
+  const parsed = Number(raw?.[key]);
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON requires positive " + key + "; configure config/hwlab-node-lanes.yaml webProbe.alertThresholds");
+  }
+  return parsed;
+}
+
 function parseAlertThresholds(value) {
+  if (!value) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON is required; configure config/hwlab-node-lanes.yaml webProbe.alertThresholds for the selected node/lane");
+  }
   const raw = (() => {
-    try { return value ? JSON.parse(value) : {}; } catch { return {}; }
+    try { return JSON.parse(value); } catch (error) { throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON is invalid JSON: " + (error instanceof Error ? error.message : String(error))); }
   })();
-  const fallback = {
-    sameOriginApiSlowMs: 10000,
-    partialApiSlowMs: 10000,
-    longLivedStreamOpenSlowMs: 10000,
-    visibleLoadingSlowMs: 10000,
-    turnTimingSampleSlackSeconds: 3,
-    sessionRailFallbackRatio: 0.5,
-  };
-  const sessionRailFallbackRatio = positiveNumber(raw.sessionRailFallbackRatio, fallback.sessionRailFallbackRatio);
+  const sessionRailFallbackRatio = requiredPositiveThreshold(raw, "sessionRailFallbackRatio");
+  if (sessionRailFallbackRatio > 1) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON sessionRailFallbackRatio must be <= 1");
+  }
   return {
-    sameOriginApiSlowMs: positiveNumber(raw.sameOriginApiSlowMs, fallback.sameOriginApiSlowMs),
-    partialApiSlowMs: positiveNumber(raw.partialApiSlowMs, fallback.partialApiSlowMs),
-    longLivedStreamOpenSlowMs: positiveNumber(raw.longLivedStreamOpenSlowMs, fallback.longLivedStreamOpenSlowMs),
-    visibleLoadingSlowMs: positiveNumber(raw.visibleLoadingSlowMs, fallback.visibleLoadingSlowMs),
-    turnTimingSampleSlackSeconds: positiveNumber(raw.turnTimingSampleSlackSeconds, fallback.turnTimingSampleSlackSeconds),
-    sessionRailFallbackRatio: Math.min(1, sessionRailFallbackRatio),
-    source: value ? "yaml-env" : "runner-default",
+    sameOriginApiSlowMs: requiredPositiveThreshold(raw, "sameOriginApiSlowMs"),
+    partialApiSlowMs: requiredPositiveThreshold(raw, "partialApiSlowMs"),
+    longLivedStreamOpenSlowMs: requiredPositiveThreshold(raw, "longLivedStreamOpenSlowMs"),
+    visibleLoadingSlowMs: requiredPositiveThreshold(raw, "visibleLoadingSlowMs"),
+    turnTimingSampleSlackSeconds: requiredPositiveThreshold(raw, "turnTimingSampleSlackSeconds"),
+    sessionRailFallbackRatio,
+    source: "yaml-env",
   };
 }
 
@@ -2216,27 +2222,33 @@ function positiveNumber(value, fallback) {
   return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
 }
 
+function requiredPositiveThreshold(raw, key) {
+  const parsed = Number(raw?.[key]);
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON requires positive " + key + "; configure config/hwlab-node-lanes.yaml webProbe.alertThresholds");
+  }
+  return parsed;
+}
+
 function parseAlertThresholds(value) {
+  if (!value) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON is required; configure config/hwlab-node-lanes.yaml webProbe.alertThresholds for the selected node/lane");
+  }
   const raw = (() => {
-    try { return value ? JSON.parse(value) : {}; } catch { return {}; }
+    try { return JSON.parse(value); } catch (error) { throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON is invalid JSON: " + (error instanceof Error ? error.message : String(error))); }
   })();
-  const fallback = {
-    sameOriginApiSlowMs: 10000,
-    partialApiSlowMs: 10000,
-    longLivedStreamOpenSlowMs: 10000,
-    visibleLoadingSlowMs: 10000,
-    turnTimingSampleSlackSeconds: 3,
-    sessionRailFallbackRatio: 0.5,
-  };
-  const sessionRailFallbackRatio = positiveNumber(raw.sessionRailFallbackRatio, fallback.sessionRailFallbackRatio);
+  const sessionRailFallbackRatio = requiredPositiveThreshold(raw, "sessionRailFallbackRatio");
+  if (sessionRailFallbackRatio > 1) {
+    throw new Error("UNIDESK_WEB_OBSERVE_ALERT_THRESHOLDS_JSON sessionRailFallbackRatio must be <= 1");
+  }
   return {
-    sameOriginApiSlowMs: positiveNumber(raw.sameOriginApiSlowMs, fallback.sameOriginApiSlowMs),
-    partialApiSlowMs: positiveNumber(raw.partialApiSlowMs, fallback.partialApiSlowMs),
-    longLivedStreamOpenSlowMs: positiveNumber(raw.longLivedStreamOpenSlowMs, fallback.longLivedStreamOpenSlowMs),
-    visibleLoadingSlowMs: positiveNumber(raw.visibleLoadingSlowMs, fallback.visibleLoadingSlowMs),
-    turnTimingSampleSlackSeconds: positiveNumber(raw.turnTimingSampleSlackSeconds, fallback.turnTimingSampleSlackSeconds),
-    sessionRailFallbackRatio: Math.min(1, sessionRailFallbackRatio),
-    source: value ? "yaml-env" : "analyzer-default",
+    sameOriginApiSlowMs: requiredPositiveThreshold(raw, "sameOriginApiSlowMs"),
+    partialApiSlowMs: requiredPositiveThreshold(raw, "partialApiSlowMs"),
+    longLivedStreamOpenSlowMs: requiredPositiveThreshold(raw, "longLivedStreamOpenSlowMs"),
+    visibleLoadingSlowMs: requiredPositiveThreshold(raw, "visibleLoadingSlowMs"),
+    turnTimingSampleSlackSeconds: requiredPositiveThreshold(raw, "turnTimingSampleSlackSeconds"),
+    sessionRailFallbackRatio,
+    source: "yaml-env",
   };
 }
 
@@ -5019,8 +5031,8 @@ function renderMarkdown(report) {
     : "- 无页面 provenance segment。";
   const ordinaryPerformanceItems = Array.isArray(report.pagePerformance?.sameOriginApiByPath) ? report.pagePerformance.sameOriginApiByPath.filter((item) => item.isLongLivedStream !== true) : [];
   const streamPerformanceItems = Array.isArray(report.pagePerformance?.sameOriginApiByPath) ? report.pagePerformance.sameOriginApiByPath.filter((item) => item.isLongLivedStream === true) : [];
-  const sameOriginApiBudgetMs = Number(report.alertThresholds?.sameOriginApiSlowMs ?? report.pagePerformance?.summary?.budgetMs ?? 10000);
-  const streamOpenBudgetMs = Number(report.alertThresholds?.longLivedStreamOpenSlowMs ?? 10000);
+  const sameOriginApiBudgetMs = Number(report.alertThresholds?.sameOriginApiSlowMs ?? report.pagePerformance?.summary?.budgetMs);
+  const streamOpenBudgetMs = Number(report.alertThresholds?.longLivedStreamOpenSlowMs);
   const performanceLines = ordinaryPerformanceItems.length > 0
     ? ordinaryPerformanceItems.slice(0, 80).map((item) => "- " + item.path + " kind=" + (item.routeKind || "same-origin-api") + " budgetMetric=" + (item.budgetMetric || "durationMs") + " samples=" + item.sampleCount + " p50=" + (item.p50Ms ?? "-") + "ms p75=" + (item.p75Ms ?? "-") + "ms p95=" + (item.p95Ms ?? "-") + "ms max=" + (item.maxMs ?? "-") + "ms >budget=" + (item.overBudgetCount ?? item.overFiveSecondCount ?? 0) + " budgetMs=" + (item.budgetMs ?? sameOriginApiBudgetMs) + " legacy>5s=" + (item.overFiveSecondCount ?? 0) + " window=" + (item.firstAt || "-") + ".." + (item.lastAt || "-")).join("\n")
     : "- 无同源 API Resource Timing 样本。";
@@ -5083,7 +5095,7 @@ function renderMarkdown(report) {
     + "- overFiveSecondSegmentCount: " + (loadingSummary.overFiveSecondSegmentCount ?? 0) + "\n"
     + "- longestContinuousSeconds: " + (loadingSummary.longestContinuousSeconds ?? 0) + "\n"
     + "- currentContinuousSeconds: " + (loadingSummary.currentContinuousSeconds ?? 0) + "\n"
-    + "- budgetSeconds: " + (loadingSummary.budgetSeconds ?? (Number(report.alertThresholds?.visibleLoadingSlowMs ?? 10000) / 1000)) + "\n"
+    + "- budgetSeconds: " + (loadingSummary.budgetSeconds ?? (Number.isFinite(Number(report.alertThresholds?.visibleLoadingSlowMs)) ? Number(report.alertThresholds.visibleLoadingSlowMs) / 1000 : "unconfigured")) + "\n"
     + "- policy: 该指标只能证明用户真实看到“加载中”的持续时间；修复必须降低真实请求/投影/渲染耗时，禁止提前展示未加载完内容来压低该指标。\n\n"
     + "#### Loading segments\n\n" + loadingSegmentLines + "\n\n"
     + "#### Loading owners\n\n" + loadingOwnerLines + "\n\n"