polish: schedule past-time confirm, recorder name sanitization, asset detail player controls

- Schedule: if start_at is more than a minute in the past, confirm()
  before submitting (operator may want to fire immediately, but
  shouldn't do it accidentally)
- Recorders: generateClipName now sanitizes the recorder name so the
  S3 key / SMB path / ffmpeg arg stays clean — spaces become
  underscores, anything outside [A-Za-z0-9._-] is dropped, capped at 40
- Asset detail: audio mute + fullscreen buttons now key off streamUrl
  state (rather than videoRef.current which is null on first render)
  so they reliably appear when a stream is available

services/mam-api/src/routes/recorders.js

@@ -65,7 +65,14 @@ function generateClipName(recorderName) {
   const hours = String(now.getHours()).padStart(2, '0');
   const minutes = String(now.getMinutes()).padStart(2, '0');
   const seconds = String(now.getSeconds()).padStart(2, '0');
-  return `${recorderName}_${year}${month}${day}_${hours}${minutes}${seconds}`;
+  // Strip filesystem-hostile characters out of the recorder name (spaces
+  // become underscores, anything outside [A-Za-z0-9._-] is dropped) so the
+  // clipName flows cleanly through S3 keys, SMB paths, and ffmpeg args.
+  const safe = String(recorderName || 'rec')
+    .replace(/\s+/g, '_')
+    .replace(/[^A-Za-z0-9._-]/g, '')
+    .slice(0, 40) || 'rec';
+  return `${safe}_${year}${month}${day}_${hours}${minutes}${seconds}`;
 }
 
 // Sanitize an operator-provided clip name so it's safe as both an S3 key

services/web-ui/public/screens-asset.jsx

@@ -286,12 +286,12 @@ function AssetDetail({ asset, onClose }) {
                 <span className="mono" style={{ fontSize: 11.5, color: "var(--text-2)", minWidth: 70 }}>{msToTimecode(currentMs)}</span>
                 <PlaybackBar current={currentMs} total={totalMs} onSeek={seek} comments={visibleComments} />
                 <span className="mono" style={{ fontSize: 11.5, color: "var(--text-3)", minWidth: 70, textAlign: "right" }}>{asset.duration}</span>
-                {videoRef.current && (
+                {streamUrl && (
                   <React.Fragment>
                     <div style={{ width: 1, height: 18, background: "var(--border-strong)" }} />
                     <button
                       className="icon-btn"
-                      title={videoRef.current.muted ? 'Unmute' : 'Mute'}
+                      title="Toggle mute"
                       onClick={function() { if (videoRef.current) { videoRef.current.muted = !videoRef.current.muted; } }}>
                       <Icon name="audio" size={14} />
                     </button>

services/web-ui/public/screens-ingest.jsx

@@ -792,15 +792,24 @@ function NewScheduleModal({ recorders, onClose, onCreated }) {
     if (!form.recorder_id)   return setErr('Pick a recorder');
     if (!form.start_at)      return setErr('Start time is required');
     if (!form.end_at)        return setErr('End time is required');
-    if (new Date(form.end_at) <= new Date(form.start_at)) return setErr('End must be after start');
+    const startD = new Date(form.start_at);
+    const endD   = new Date(form.end_at);
+    if (endD <= startD) return setErr('End must be after start');
+
+    // Warn (but allow) start times in the past — the scheduler tick will fire
+    // them immediately, which is occasionally what the operator wants
+    // (e.g. "record the next 30 minutes starting now").
+    if (startD < new Date(Date.now() - 60_000)) {
+      if (!confirm('Start time is in the past — recorder will fire immediately when saved.\nContinue?')) return;
+    }
 
     // Datetime-local inputs are in the browser's local zone; ship as ISO so
     // Postgres stores them as TIMESTAMPTZ properly.
     const body = {
       name:        form.name.trim(),
       recorder_id: form.recorder_id,
-      start_at:    new Date(form.start_at).toISOString(),
+      start_at:    startD.toISOString(),
-      end_at:      new Date(form.end_at).toISOString(),
+      end_at:      endD.toISOString(),
       recurrence:  form.recurrence,
     };