fix: clip queue resolves row index by filename, not stored _idx

clipQueue entries snapshotted fileIdx (= _idx) when the queue was armed,
but _idx is reassigned positionally on every load(), and pollStatus()
reloads the list whenever a recording starts, stops, or rolls over to a
new split file. With the newest-first sort a rollover shifts every index
by one, so an armed queue then pre-filled the wrong row's cut fields and
"Open in file" (O) opened the wrong row while streaming the clip's file
into it — during exactly the workflow of reviewing yesterday while
today's recording runs.

Store only the filename in queue entries and resolve the row index at
use time (fileIdxByName); if the file left the listing, Open in file
does nothing instead of acting on a wrong row.

Also drop seekToSection's sectionIdx parameter: the only remaining
caller passed null, leaving the announce branch dead since chips moved
to clip playback.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

webui.html

@@ -235,6 +235,12 @@ function setCutFields(idx, startSec, endSec) {
   if (endEl && endSec != null) endEl.value = fmtDur(endSec);
 }
 
+// Row index for a filename, resolved at use time: _idx values are reassigned
+// positionally on every load(), and pollStatus() reloads the list whenever a
+// recording starts/stops/rolls over — a stored index would point one row off
+// after that. Null when the file is gone from the current listing.
+const fileIdxByName = name => allFiles.find(f => f.name === name)?._idx ?? null;
+
 // idx -> filename, for live-status polling
 const recMap = new Map();
 // idx -> [{start,end}], populated after analysis
@@ -325,7 +331,7 @@ function parseTime(s) {
   return parts[0];
 }
 
-function seekToSection(idx, filename, startSec, endSec, sectionIdx) {
+function seekToSection(idx, filename, startSec, endSec) {
   const pbtn = document.getElementById('pbtn-'+idx);
   if (pbtn.getAttribute('aria-expanded') !== 'true') togglePlayer(idx, filename);
   activePlayerIdx = idx;
@@ -336,10 +342,6 @@ function seekToSection(idx, filename, startSec, endSec, sectionIdx) {
   if (audio.readyState >= 1) doSeek();
   else audio.addEventListener('loadedmetadata', doSeek, {once: true});
   setCutFields(idx, startSec, endSec);
-  if (sectionIdx != null) {
-    const total = (sectionMap.get(idx) || []).length;
-    announce(`Section ${sectionIdx + 1} of ${total}: ${fmtDur(startSec)} to ${fmtDur(endSec)}`);
-  }
 }
 
 // --- clip player -----------------------------------------------------------
@@ -390,7 +392,8 @@ function playClip(i, byScore) {
   label.title = `${c.filename} @ ${fmtDur(c.start)}–${fmtDur(c.end)}`;
   document.getElementById('clip-bar').hidden = false;
   document.body.classList.add('clip-open');
-  setCutFields(c.fileIdx, c.start, c.end);
+  const rowIdx = fileIdxByName(c.filename);
+  if (rowIdx != null) setCutFields(rowIdx, c.start, c.end);
   announce(text);
 }
 
@@ -409,7 +412,7 @@ function playFileSection(idx, filename, si) {
   const secs  = sectionMap.get(idx) || [];
   const f     = allFiles.find(f => f._idx === idx);
   const epoch = f ? fileStartEpoch(f.date) : null;
-  clipQueue = secs.map(s => ({fileIdx: idx, filename, start: s.start, end: s.end, score: s.score,
+  clipQueue = secs.map(s => ({filename, start: s.start, end: s.end, score: s.score,
                               absStart: epoch != null ? epoch + s.start : null}));
   scoreCursor = -1;                 // explicit jump: next U/I re-anchors here
   playClip(si);
@@ -468,15 +471,17 @@ document.getElementById('clip-audio').addEventListener('ended', () => {
 function openClipInFile() {
   const c = clipQueue[clipCursor];
   if (!c) return;
+  const idx = fileIdxByName(c.filename);
+  if (idx == null) return;
   document.getElementById('clip-audio').pause();
-  const row = document.getElementById('row-' + c.fileIdx);
+  const row = document.getElementById('row-' + idx);
   if (row) {
     const tbl = row.closest('table');
     if (tbl && tbl.hidden)   // file's day is collapsed: expand it
       document.getElementById('daytgl-' + tbl.id.slice('daytbl-'.length))?.click();
     row.scrollIntoView({block: 'center'});
   }
-  seekToSection(c.fileIdx, c.filename, c.start, c.end, null);
+  seekToSection(idx, c.filename, c.start, c.end);
 }
 document.getElementById('clip-context').addEventListener('click', openClipInFile);
 
@@ -1024,7 +1029,6 @@ async function dayHighlights(dayId, analyzableFiles) {
   positioned.forEach(({ f, data, fileStart }) => {
     (data.sections || []).forEach(s => {
       dayActiveSections.push({
-        fileIdx: f._idx,
         filename: f.name,
         start: s.start,
         end: s.end,