ui: surface per-channel ZC Freq (and ">100") in event modals

The PDF report shows per-channel ZC Freq alongside PPV in the stats
block, but neither modal exposed it.  Now that the sidecar projection
carries zc_freq_hz + zc_freq_above_range, plumb them through:

- sfm_webapp.html: inline suffix on existing Peaks cells, e.g.
  "Tran  0.04500 in/s · >100 Hz".  Empty suffix when no ZC is
  available (legacy events without a preserved .TXT).

- event_browser.html: new ZC Freq column on the per-channel stats
  table.  Required adding a parallel sidecar fetch in loadEvent()
  (waveform.json alone doesn't carry bw_report).  Fetch failure is
  non-fatal — falls back to "—" in the new column.

Above-range ZC peaks (BW ">100 Hz") render with a literal ">"
prefix mirroring the PDF, so operators don't have to generate the
PDF to see when a channel hit the zero-crossing ceiling.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

sfm/event_browser.html

@@ -499,6 +499,14 @@ async function loadEvent(eventId) {
   renderEventList();
   setStatus('Loading waveform…');
   try {
+    // Sidecar fetch runs in parallel — its bw_report block carries ZC
+    // Freq + above-range flags + sensor-check results that the per-
+    // channel stats table surfaces.  Failures are non-fatal (legacy
+    // events without a preserved .TXT have no sidecar bw_report).
+    const sidecarP = fetch(`${apiBase}/db/events/${eventId}/sidecar`)
+      .then(r => r.ok ? r.json() : null)
+      .catch(() => null);
+
     const r = await fetch(`${apiBase}/db/events/${eventId}/waveform.json`);
     if (!r.ok) {
       if (r.status === 404) {
@@ -511,7 +519,8 @@ async function loadEvent(eventId) {
     renderWaveform(data);
     // Also fetch metadata from the events list for richer header
     const ev = allEvents.find(e => e.id === eventId);
-    renderMeta(data, ev);
+    const sidecar = await sidecarP;
+    renderMeta(data, ev, sidecar);
     setStatus(`Event loaded.`, 'ok');
   } catch (e) {
     setStatus(`Failed to load event: ${e.message}`, 'error');
@@ -528,7 +537,7 @@ function showEmpty(msg) {
   charts = {};
 }
 
-function renderMeta(data, ev) {
+function renderMeta(data, ev, sidecar) {
   const metaDiv = document.getElementById('event-meta');
   const fields = [
     ['Serial',      data.serial || ev?.serial || '—'],
@@ -543,14 +552,20 @@ function renderMeta(data, ev) {
   ];
 
   // Per-channel stats table mirroring the printout's middle block.
-  // Pulls per-channel PPV from the events row (DB columns) and additional
+  // PPV from the events DB row; ZC Freq + saturation flags from the
-  // details (peak time, peak accel, peak displacement, sensor check) from
+  // sidecar's bw_report block (when a .TXT was preserved on ingest).
-  // bw_report when present.
+  const bwrPeaks = (sidecar?.bw_report || {}).peaks || {};
+  const bwrMic   = (sidecar?.bw_report || {}).mic   || {};
   const fmt = v => (v == null ? '—' : (typeof v === 'number' ? v.toFixed(3) : v));
+  const fmtZc = bwr => {
+    if (!bwr || bwr.zc_freq_hz == null) return '—';
+    const prefix = bwr.zc_freq_above_range ? '>' : '';
+    return `${prefix}${Math.round(bwr.zc_freq_hz)} Hz`;
+  };
   const rows = [
-    ['Tran', ev?.tran_ppv],
+    ['Tran', ev?.tran_ppv, fmtZc(bwrPeaks.tran)],
-    ['Vert', ev?.vert_ppv],
+    ['Vert', ev?.vert_ppv, fmtZc(bwrPeaks.vert)],
-    ['Long', ev?.long_ppv],
+    ['Long', ev?.long_ppv, fmtZc(bwrPeaks.long)],
   ];
   // Mic display honors the current user preference (dBL default).
   // mic_ppv is stored as raw psi on series3 events; convert when needed.
@@ -568,11 +583,11 @@ function renderMeta(data, ev) {
   const statsHtml = `
     <table class="stats-table">
       <thead>
-        <tr><th>Channel</th><th>PPV (in/s)</th></tr>
+        <tr><th>Channel</th><th>PPV (in/s)</th><th>ZC Freq</th></tr>
       </thead>
       <tbody>
-        ${rows.map(([ch, ppv]) => `<tr><td>${ch}</td><td>${fmt(ppv)}</td></tr>`).join('')}
+        ${rows.map(([ch, ppv, zc]) => `<tr><td>${ch}</td><td>${fmt(ppv)}</td><td>${zc}</td></tr>`).join('')}
-        <tr><td>MicL</td><td>${micStr}</td></tr>
+        <tr><td>MicL</td><td>${micStr}</td><td>${fmtZc(bwrMic)}</td></tr>
       </tbody>
     </table>
   `;

sfm/sfm_webapp.html

@@ -2886,6 +2886,12 @@ function _renderSidecar(data) {
   const bw   = data.blastware    || {};
   const src  = data.source       || {};
   const rev  = data.review       || {};
+  // bw_report carries the per-channel ASCII-derived stats (ZC Freq,
+  // saturation flags, peak time, etc.).  Only present on events
+  // ingested with a preserved .TXT (post-2026-05-27); falls back to
+  // empty for legacy events.
+  const bwrPeaks = (data.bw_report || {}).peaks || {};
+  const bwrMic   = (data.bw_report || {}).mic   || {};
 
   document.getElementById('sc-title').textContent = `Event — ${bw.filename || ev.waveform_key || 'unknown'}`;
 
@@ -2918,11 +2924,19 @@ function _renderSidecar(data) {
   document.getElementById('sc-f-sr').textContent       = (ev.sample_rate ?? '—') + (ev.sample_rate ? ' sps' : '');
   document.getElementById('sc-f-key').textContent      = ev.waveform_key    || '—';
 
-  document.getElementById('sc-f-tran').textContent     = fmtPpv(pv.transverse);
+  // Suffix with " · {prefix}{N} Hz" when bw_report has a ZC Freq.
-  document.getElementById('sc-f-vert').textContent     = fmtPpv(pv.vertical);
+  // Above-range ZC peaks (BW ">100 Hz") get a literal ">" prefix so
-  document.getElementById('sc-f-long').textContent     = fmtPpv(pv.longitudinal);
+  // operators see the same indicator the PDF shows.
+  const fmtZc = bwr => {
+    if (!bwr || bwr.zc_freq_hz == null) return '';
+    const prefix = bwr.zc_freq_above_range ? '>' : '';
+    return ` · ${prefix}${Math.round(bwr.zc_freq_hz)} Hz`;
+  };
+  document.getElementById('sc-f-tran').textContent     = fmtPpv(pv.transverse)   + fmtZc(bwrPeaks.tran);
+  document.getElementById('sc-f-vert').textContent     = fmtPpv(pv.vertical)     + fmtZc(bwrPeaks.vert);
+  document.getElementById('sc-f-long').textContent     = fmtPpv(pv.longitudinal) + fmtZc(bwrPeaks.long);
   document.getElementById('sc-f-pvs').textContent      = fmtPpv(pv.vector_sum);
-  document.getElementById('sc-f-mic').textContent      = fmtMic(pv.mic_psi);
+  document.getElementById('sc-f-mic').textContent      = fmtMic(pv.mic_psi)      + fmtZc(bwrMic);
 
   document.getElementById('sc-f-project').textContent  = pi.project         || '—';
   document.getElementById('sc-f-client').textContent   = pi.client          || '—';