diff --git a/CLAUDE.md b/CLAUDE.md
index 63e1455..b981d68 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -38,10 +38,10 @@ Dependencies: `requests` (streams), `numpy` + `soundfile` (FLAC output and FLAC
 - Serving: `_stream()` (Range support), `_copy_to_response()`, `_safe_path()` (path traversal guard).
 
 `webui.html` (one `<script>` block):
-- Clip review: `clipQueue`/`clipCursor`/`scoreCursor` globals, `playClip()`, `playFileSection()`, `hideClipBar()`; markup is the `#clip-bar` div. The clip label shows wall-clock occurrence time + dB prominence + position (`17:09:56 to 17:09:57 · +30 dB (30 / 426 by time)`): queue entries carry `absStart` (epoch s), derived from `fileStartEpoch(f.date)` — the filename clock — with in-file offsets as fallback for non-standard names; only the filename/in-file offset lives in the tooltip now. **Queue entries carry the filename, never a row index:** `_idx` is reassigned positionally on every `load()`, and `pollStatus()` reloads whenever a recording starts/stops/rolls over, so a stored index goes stale mid-review (a past bug had "Open in file"/cut fields target the row one off after a split rollover). Resolve at use time via `fileIdxByName()`. **`playClip()` builds one `text` string used for both `label.textContent` and the `announce()` aria-live message** — they must never diverge (a past bug had the announcement read `Clip N of M: …` while the label read the wall-clock form). **Two cursors, deliberately independent:** `clipCursor` is the time-order position and follows every play; `scoreCursor` is the loudness walk's own position in `scoreOrder()` and is moved *only* by U/I (and "highlights only" auto-advance) in `stepClip`'s by-score branch — J/K must never touch it, so a J/K detour to review nearby clips leaves the loudness walk's place intact and the next U/I resumes the ranking where it left off. `scoreCursor` resets to `-1` on every explicit jump / queue (re-)arm (`hideClipBar`, `playFileSection`, `jumpToDaySection`, both day-highlights arm points), so the next U/I re-anchors on `clipCursor` (the section just selected) else the loudest. `playClip(i, byScore)`: when `byScore` the count shows `scoreCursor` (rank, suffix "by loudness"), else `i` (time-order index, suffix "by time") — the suffix tells the blind user which dimension the count is in. `stepClip`'s by-score branch passes `byScore=true`; every other caller (chip click, J/K, Prev/Next) leaves it false.
-- Day review: `dayHighlights()` builds `dayActiveSections` (chronological); `jumpToDaySection()` arms the queue. Section `absStart` comes from `fileStartEpoch(f.date)` (filename clock), mtime−duration only as fallback. **The user is blind and uses a screen reader — there is deliberately no day-timeline SVG** (one existed and was removed on request as useless); the highlights panel is linear text/buttons: summary line → key-hint note → chips toggle → chips. Do not add decorative visualizations; any future graphic must be aria-hidden and must not be the only carrier of information. Chip lists longer than 12 are collapsed behind an `aria-expanded` toggle button (the `.chips[hidden]{display:none}` rule is required — the author-level `display:flex` on `.chips` would otherwise override the UA `[hidden]` rule). Group `aria-label`s stay short ("Day loud sections") — the J/K/U/I key explanation lives only in the visible note, per user feedback against repeating info text in labels. The Highlights button is a collapse/expand toggle (`setHlExpanded()` keeps arrow + `aria-expanded` in sync, also from the day-collapse path): a built panel is kept and re-armed from `dayHlSections` instead of recomputing, keyed by `hlRow.dataset.loaded = hlParams()` (margin|gap|minDur string) so changed params force a re-run. The `#dayhls-<dayId>` "· analysed" suffix appears when every file's `cached_analysis` passes `cachedParamsMatch()`; `fetchAnalysis()` updates `f.cached_analysis` client-side so the marker survives re-renders without refetching `/api/files`. **`aria-label` on a button replaces its visible content for screen readers** — any status text rendered inside a labelled button (like the analysed suffix) must be mirrored into the label (render path + the end of `dayHighlights()`), or the blind user never hears it. Likewise, the accessible text of a button built as `aria-hidden arrow span + text node` must not start the text node with a space (the hidden arrow drops out and the leading space reads as an indent) — keep separator spaces inside the aria-hidden span.
+- Clip review: `clipQueue`/`clipCursor`/`scoreCursor` globals, `playClip()`, `playFileSection()`, `hideClipBar()`; markup is the `#clip-bar` div. The clip label shows wall-clock occurrence time + dB prominence + position (`17:09:56 to 17:09:57 · +30 dB (30 / 426 by time)`): queue entries carry `absStart` (epoch s), derived from `fileStartEpoch(f.date)` — the filename clock — with in-file offsets as fallback for non-standard names; only the filename/in-file offset lives in the tooltip now. **Queue entries carry the filename, never a row index:** `_idx` is reassigned positionally on every `load()`, and `pollStatus()` reloads whenever a recording starts/stops/rolls over, so a stored index goes stale mid-review (a past bug had "Open in file"/cut fields target the row one off after a split rollover). Resolve at use time via `fileIdxByName()`. **`playClip()` builds one `text` string used for both `label.textContent` and the `announce()` aria-live message** — they must never diverge (a past bug had the announcement read `Clip N of M: …` while the label read the wall-clock form). **Two cursors, deliberately independent:** `clipCursor` is the time-order position and follows every play; `scoreCursor` is the loudness walk's own position in `scoreOrder()` and is moved *only* by U/I (and "highlights only" auto-advance) in `stepClip`'s by-score branch — J/K must never touch it, so a J/K detour to review nearby clips leaves the loudness walk's place intact and the next U/I resumes the ranking where it left off. `scoreCursor` resets to `-1` on every explicit jump / queue (re-)arm (`hideClipBar`, `playFileSection`, `jumpToDaySection`, both day-highlights arm points), so the next U/I re-anchors on `clipCursor` (the section just selected) else the loudest. `playClip(i, byScore)`: when `byScore` the count shows `scoreCursor` (rank, suffix "by loudness"), else `i` (time-order index, suffix "by time") — the suffix tells the blind user which dimension the count is in. `stepClip`'s by-score branch passes `byScore=true`; every other caller (chip click, J/K, Prev/Next) leaves it false. Both U/I walks — `stepClip`'s by-score branch and the in-player branch of the keydown handler — share `nextInOrder(order, pos, dir, jump)` for the stepping arithmetic (returns `null` at either end); they differ only in what anchors `pos` and what "play" means, and must not re-inline it.
+- Day review: `dayHighlights()` builds the chronological cross-file section list; `armDayQueue(dayId, sections)` is the single place that points the queue at a day (sets `dayActiveSections`/`dayActiveId`/`clipQueue` and resets both cursors) — used by the fresh-build path and the re-open-a-kept-panel path alike. `jumpToDaySection()` arms the queue. Section `absStart` comes from `fileStartEpoch(f.date)` (filename clock), mtime−duration only as fallback. **The user is blind and uses a screen reader — there is deliberately no day-timeline SVG** (one existed and was removed on request as useless); the highlights panel is linear text/buttons: summary line → key-hint note → chips toggle → chips. Do not add decorative visualizations; any future graphic must be aria-hidden and must not be the only carrier of information. Chip lists longer than 12 are collapsed behind an `aria-expanded` toggle button (the `.chips[hidden]{display:none}` rule is required — the author-level `display:flex` on `.chips` would otherwise override the UA `[hidden]` rule). Group `aria-label`s stay short ("Day loud sections") — the J/K/U/I key explanation lives only in the visible note, per user feedback against repeating info text in labels. The Highlights button is a collapse/expand toggle (`setHlExpanded()` keeps arrow + `aria-expanded` in sync, also from the day-collapse path): a built panel is kept and re-armed from `dayHlSections` instead of recomputing, keyed by `hlRow.dataset.loaded = hlParams()` (margin|gap|minDur string) so changed params force a re-run. The `#dayhls-<dayId>` "· analysed" suffix appears when every file's `cached_analysis` passes `cachedParamsMatch()`; `fetchAnalysis()` updates `f.cached_analysis` client-side so the marker survives re-renders without refetching `/api/files`. **`aria-label` on a button replaces its visible content for screen readers** — any status text rendered inside a labelled button (like the analysed suffix) must be mirrored into the label (render path + the end of `dayHighlights()`), or the blind user never hears it. Likewise, the accessible text of a button built as `aria-hidden arrow span + text node` must not start the text node with a space (the hidden arrow drops out and the leading space reads as an indent) — keep separator spaces inside the aria-hidden span.
 - J/K/U/I/O: single document-level `keydown` listener — clip queue takes priority, in-player `currentTime` stepping is the fallback when no queue is armed; O calls `openClipInFile()` (shared with the "Open in file" button). J/K (and Prev/Next) always step in time order; U/I walk the loudest-first ranking from `scoreOrder()` — no top-N cutoff (the `#clip-top` input and `#clip-hl-only` checkbox were removed deliberately; J/K must never be affected by an auto-advance/highlights setting). Auto-advance is the `input[name="clip-adv"]` radio (off / next in time / next by loudness), read by `advanceMode()`; `stepClip(dir, byScore)` is the shared queue-stepping path. In-player U/I anchor the ranking on the section under the playhead, else start at the loudest.
-- Analysis: `fetchAnalysis()` (session `analysisCache`), `analyse()` (per-row render: meta line with section count + params, then chips — no waveform SVG, see day-review note on the blind user), `cachedParamsMatch()` (autoload guard).
+- Analysis: `fetchAnalysis()` (session `analysisCache`), `analyse()` (per-row render: meta line with section count + params, then chips — no waveform SVG, see day-review note on the blind user; its `btn` argument is optional), `cachedParamsMatch()` (autoload guard). `analysisParams()` is the only reader of the three control inputs — no hardcoded client-side defaults, so web.py's constants stay the single source of truth via `/api/config`; `hlParams()` is just its values joined.
 
 ## Verifying changes
 
diff --git a/webui.html b/webui.html
index 90a2e2e..16d3b21 100644
--- a/webui.html
+++ b/webui.html
@@ -61,15 +61,14 @@ a.dl:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-rad
 .actions{display:flex;gap:6px;align-items:center}
 button.del{color:var(--red);border-color:#7f1d1d}
 button.del:hover:not(:disabled){background:#2d0808}
-/* waveform */
+/* analysis result box + section chips */
 .wbox{background:var(--surf);border:1px solid var(--brd);border-radius:6px;padding:10px 12px}
 .chips{display:flex;flex-wrap:wrap;gap:5px;margin-top:8px}
 .chips[hidden]{display:none}
 .chip{background:#431407;color:var(--orange);border:1px solid #7c2d12;border-radius:4px;
-  padding:2px 8px;font-size:11px;font-family:ui-monospace,monospace}
-button.chip{cursor:pointer}
-button.chip:hover{background:#6c1f08;border-color:#9a3412}
-button.chip:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
+  padding:2px 8px;font-size:11px;font-family:ui-monospace,monospace;cursor:pointer}
+.chip:hover{background:#6c1f08;border-color:#9a3412}
+.chip:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
 .quiet{color:var(--muted);font-size:12px;margin-top:6px}
 .spin{color:var(--muted);font-style:italic;font-size:12px;padding:6px 0}
 .prog-bar{height:3px;background:var(--brd);border-radius:2px;margin:6px 0 4px;overflow:hidden}
@@ -240,9 +239,8 @@ function setCutFields(idx, startSec, endSec) {
 // 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;
+const fileNameByIdx = idx => allFiles.find(f => f._idx === idx)?.name ?? '';
 
-// idx -> filename, for live-status polling
-const recMap = new Map();
 // idx -> [{start,end}], populated after analysis
 const sectionMap = new Map();
 let activePlayerIdx = null;
@@ -257,11 +255,19 @@ let dayActiveId = null;
 // and re-expanding it re-arms J/K without recomputing
 const dayHlSections = new Map();
 
-// Current analysis params as one string; a highlights panel built with other
-// values is stale and gets recomputed on the next expand
-const hlParams = () =>
-  ['margin-input', 'min-gap-input', 'min-duration-input']
-    .map(id => document.getElementById(id).value).join('|');
+// The three analysis controls, read straight from the DOM. Deliberately no
+// hardcoded fallbacks: the inputs are seeded from /api/config at startup, so
+// web.py's MARGIN_DB / MIN_GAP_SECONDS / MIN_DURATION_SECONDS stay the single
+// source of truth. An empty input sends an empty param, which _qs_float()
+// falls back to the server default for.
+const analysisParams = () => ({
+  margin: document.getElementById('margin-input').value,
+  minGap: document.getElementById('min-gap-input').value,
+  minDur: document.getElementById('min-duration-input').value,
+});
+// Same values as one string; a highlights panel built with other values is
+// stale and gets recomputed on the next expand
+const hlParams = () => Object.values(analysisParams()).join('|');
 
 function setHlExpanded(dayId, exp) {
   const btn = document.getElementById('dayhln-' + dayId);
@@ -290,7 +296,7 @@ function closePlayer(idx) {
   if (btn) {
     btn.setAttribute('aria-expanded','false');
     btn.textContent = 'Play';
-    btn.setAttribute('aria-label','Play '+(recMap.get(idx) || ''));
+    btn.setAttribute('aria-label','Play '+fileNameByIdx(idx));
   }
 }
 
@@ -428,6 +434,19 @@ function scoreOrder(secs) {
     .map(r => r.i);
 }
 
+// Step a position within an ordering: pos + dir, or straight to the extreme in
+// that direction when jump. Returns null when the step runs off either end.
+// pos === -1 means "not anchored yet" — start at the first entry going forward,
+// or off the front going backward so the caller announces the boundary.
+// Shared by both U/I walks (clip queue and in-player); they differ only in what
+// the anchor is and what "play" means, and drifting apart is exactly how the
+// two would stop agreeing.
+function nextInOrder(order, pos, dir, jump) {
+  const next = jump ? (dir > 0 ? order.length - 1 : 0)
+                    : pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
+  return (next >= 0 && next < order.length) ? next : null;
+}
+
 const advanceMode = () =>
   document.querySelector('input[name="clip-adv"]:checked')?.value || 'off';
 
@@ -442,15 +461,13 @@ function stepClip(dir, byScore, jump) {
     // the walk hasn't started since the queue was armed or an explicit jump —
     // anchor on the section currently selected (clipCursor), else the loudest.
     const order = scoreOrder(clipQueue);
-    let next;
-    if (jump) next = dir > 0 ? order.length - 1 : 0;
-    else if (scoreCursor !== -1) next = scoreCursor + dir;
-    else {
-      const anchor = clipCursor >= 0 ? order.indexOf(clipCursor) : -1;
-      next = anchor === -1 ? (dir > 0 ? 0 : -1) : anchor + dir;
-    }
-    if (next >= 0 && next < order.length) { scoreCursor = next; playClip(order[next], true); }
-    else announce(dir < 0 ? 'Loudest highlight reached' : 'End of highlights');
+    const pos   = scoreCursor !== -1 ? scoreCursor
+                : clipCursor >= 0    ? order.indexOf(clipCursor)
+                : -1;
+    const next  = nextInOrder(order, pos, dir, jump);
+    if (next === null) { announce(dir < 0 ? 'Loudest highlight reached' : 'End of highlights'); return; }
+    scoreCursor = next;
+    playClip(order[next], true);
     return;
   }
   // J/K (time order) deliberately does NOT touch scoreCursor.
@@ -507,17 +524,20 @@ async function fetchAnalysis(filename, margin, minGap, minDur, force = false) {
   return d;
 }
 
+// btn is optional: the deferred-autoload path has one in the cell already,
+// but a caller with no button still gets one back on the error path so the
+// analysis stays retryable.
 async function analyse(idx, filename, cell, btn, force = false) {
-  btn.disabled = true;
-  btn.textContent = '…';
+  if (btn) { btn.disabled = true; btn.textContent = '…'; }
   cell.innerHTML = '<div class="spin" aria-live="polite" aria-busy="true">Analysing…</div>';
-  const margin = document.getElementById('margin-input').value || '12';
-  const minGap = document.getElementById('min-gap-input').value || '2';
-  const minDur = document.getElementById('min-duration-input').value || '0.5';
+  const {margin, minGap, minDur} = analysisParams();
   const restoreBtn = () => {
-    btn.textContent = 'Analyse'; btn.disabled = false;
-    btn.onclick = () => analyse(idx, filename, cell, btn);
-    if (!cell.contains(btn)) cell.appendChild(btn);
+    const b = btn || document.createElement('button');
+    b.textContent = 'Analyse';
+    b.disabled = false;
+    b.setAttribute('aria-label', `Analyse loudness of ${filename}`);
+    b.onclick = () => analyse(idx, filename, cell, b);
+    if (!cell.contains(b)) cell.appendChild(b);
   };
   try {
     const d = await fetchAnalysis(filename, margin, minGap, minDur, force);
@@ -611,12 +631,12 @@ document.addEventListener('keydown', e => {
     const order  = scoreOrder(all);
     const curIdx = all.findIndex(s => cur >= s.start - preroll - 0.5 && cur <= s.end + 0.5);
     const pos    = curIdx === -1 ? -1 : order.indexOf(curIdx);
-    const next   = jump ? (dir > 0 ? order.length - 1 : 0)
-                        : pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
-    if (next >= 0 && next < order.length)
-      jumpTo(all[order[next]], next, order.length, 'Highlight');
-    else
+    const next   = nextInOrder(order, pos, dir, jump);
+    if (next === null) {
       announce(dir < 0 ? 'Loudest highlight reached' : 'End of highlights');
+      return;
+    }
+    jumpTo(all[order[next]], next, order.length, 'Highlight');
     return;
   }
 
@@ -648,7 +668,6 @@ async function deleteFile(idx, filename) {
     const r = await fetch('/api/files/'+encodeURIComponent(filename), {method:'DELETE'});
     if (r.ok) {
       allFiles = allFiles.filter(f => f._idx !== idx);
-      recMap.delete(idx);
       for (const k of [...analysisCache.keys()])
         if (k.startsWith(filename + '|')) analysisCache.delete(k);
       applyFilters();
@@ -689,12 +708,11 @@ function cachedParamsMatch(ca) {
 function autoloadDayAnalyses(dayId) {
   document.querySelectorAll('#daytbl-' + dayId + ' td[data-autoload="1"]').forEach(cell => {
     cell.removeAttribute('data-autoload');
-    const btn = cell.querySelector('button') || document.createElement('button');
-    analyse(Number(cell.dataset.idx), cell.dataset.fname, cell, btn);
+    analyse(Number(cell.dataset.idx), cell.dataset.fname, cell, cell.querySelector('button'));
   });
 }
 
-function _attachFileRowHandlers(f, isRec, expanded, dayId) {
+function _attachFileRowHandlers(f, isRec, expanded) {
   const i = f._idx;
   const ext = f.ext;
   const canAnalyse = ext === 'wav' || ext === 'flac';
@@ -754,14 +772,11 @@ function _attachFileRowHandlers(f, isRec, expanded, dayId) {
     document.getElementById('delbtn-'+i)
       .addEventListener('click', () => deleteFile(i, f.name));
   }
-
-  recMap.set(i, f.name);
 }
 
 function renderFiles(files) {
   const container = document.getElementById('tbody');
   container.innerHTML = '';
-  recMap.clear();
   sectionMap.clear();
 
   const total   = allFiles.length;
@@ -914,7 +929,7 @@ function renderFiles(files) {
       </td>`;
       dayTbody.appendChild(prow);
 
-      _attachFileRowHandlers(f, isRec, expanded, dayId);
+      _attachFileRowHandlers(f, isRec, expanded);
     });
 
     // Day toggle handler
@@ -952,11 +967,7 @@ function renderFiles(files) {
         if (hlRow.dataset.loaded === hlParams()) { // re-open and re-arm J/K
           hlRow.hidden = false;
           setHlExpanded(dayId, true);
-          dayActiveSections = dayHlSections.get(dayId) || [];
-          dayActiveId = dayId;
-          clipQueue = dayActiveSections;
-          clipCursor = -1;
-          scoreCursor = -1;
+          armDayQueue(dayId, dayHlSections.get(dayId) || []);
           return;
         }
         dayHighlights(dayId, hlFiles);
@@ -985,9 +996,7 @@ async function dayHighlights(dayId, analyzableFiles) {
   progWrap.appendChild(progBar); progWrap.appendChild(progFile);
   contentEl.innerHTML = ''; contentEl.appendChild(progWrap);
 
-  const margin = document.getElementById('margin-input').value || '12';
-  const minGap = document.getElementById('min-gap-input').value || '2';
-  const minDur = document.getElementById('min-duration-input').value || '0.5';
+  const {margin, minGap, minDur} = analysisParams();
 
   const results = [];
   let nCached = 0, nLive = 0;
@@ -1029,10 +1038,10 @@ async function dayHighlights(dayId, analyzableFiles) {
   const totalSecs = positioned.reduce((a, r) => a + r.data.sections.length, 0);
 
   // Build cross-file section list for J/K navigation and chips
-  dayActiveSections = [];
+  const sections = [];
   positioned.forEach(({ f, data, fileStart }) => {
     (data.sections || []).forEach(s => {
-      dayActiveSections.push({
+      sections.push({
         filename: f.name,
         start: s.start,
         end: s.end,
@@ -1041,12 +1050,9 @@ async function dayHighlights(dayId, analyzableFiles) {
       });
     });
   });
-  dayActiveSections.sort((a, b) => a.absStart - b.absStart);
-  dayActiveId = dayId;
+  sections.sort((a, b) => a.absStart - b.absStart);
   // Arm the clip queue so J/K steps through the day immediately
-  clipQueue = dayActiveSections;
-  clipCursor = -1;
-  scoreCursor = -1;
+  armDayQueue(dayId, sections);
 
   const box = document.createElement('div');
   box.className = 'wbox';
@@ -1130,6 +1136,19 @@ async function dayHighlights(dayId, analyzableFiles) {
   if (btn) btn.disabled = false;
 }
 
+// Point the clip queue at a day's cross-file section list, from either the
+// fresh-build path or the re-open-a-kept-panel path. Five coupled globals set
+// in two places is how the stale-_idx and diverging-label bugs happened.
+// Both cursors reset: nothing is selected yet, and the next U/I must re-anchor
+// here rather than resume a walk through the previous queue.
+function armDayQueue(dayId, sections) {
+  dayActiveSections = sections;
+  dayActiveId       = dayId;
+  clipQueue         = sections;
+  clipCursor        = -1;
+  scoreCursor       = -1;
+}
+
 function jumpToDaySection(si) {
   if (si < 0 || si >= dayActiveSections.length) return;
   clipQueue = dayActiveSections;
@@ -1176,9 +1195,11 @@ async function pollStatus() {
   try {
     const s = await (await fetch('/api/status')).json();
     const active = new Set(s.active || []);
-    recMap.forEach((filename, idx) => {
-      const badge = document.getElementById('rec-'+idx);
-      if (badge) badge.hidden = !active.has(filename);
+    // Rows not currently rendered (filtered out, collapsed day) have no
+    // badge element, so getElementById skips them.
+    allFiles.forEach(f => {
+      const badge = document.getElementById('rec-'+f._idx);
+      if (badge) badge.hidden = !active.has(f.name);
     });
     // Active set changed (recording started/stopped or rolled over to a new
     // split file): refresh the list so new files appear — but never yank the