Fix H5/H6/M21/L37-40/L47/L55/L68/L72/L76/L91/L98/L108/L165/L166 audit items

H5: HistoryEntry now stores formatId+formatHasAudio; redownload passes them
    back to addFromUrl so the original yt-dlp format is reused, not guessed.
    Compound quality labels stripped to the preset prefix for old history.
L72: thumbnail now passed in redownload so re-queued rows keep their art.
H6: TerminalView log capped at MAX_LOG_LINES=2000 to prevent unbounded growth.
M21: --audio-quality omitted for lossless audioFormats (flac/wav).
L166: fmtEta hour rollover fixed in all 3 locations -- 2h00:00 not 120:00.
L165: queueStats formatSpeed precision aligned with fmtBytes.
L55: QueueItem suppresses sizeLabel when already in probed-format quality label.
L47: probeMeta null sends empty meta event so Resolving clears via SR6.
L68: notifiedBackground resets on window show for subsequent close-while-downloading.
L76: dup warning falls back to URL when title is still a placeholder.
L91: SettingsView onFormatSelect uses indexOf instead of unsafe tuple cast.
L98: Embed chapters field gets a hint text.
L108: BrowserWindow created with explicit title AeroFetch.
L37: pure formatters extracted to src/main/lib/formatters.ts and unit-tested.
L38: buildArgs test covers webm thumbnail suppression.
L39: CROP_SQUARE_PPA test is structural not exact-string.
L40: looksLikeUrl/looksLikeSingleVideo extracted to src/renderer/src/lib/urlHelpers.ts.

typecheck + 242 tests + eslint + prettier green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/main/buildArgs.ts

@@ -404,7 +404,11 @@ export function buildArgs(
   args.push(...postProcessArgs(opts, o))
 
   if (opts.kind === 'audio') {
-    args.push('-x', '--audio-format', o.audioFormat, '--audio-quality', audioQuality(opts.quality))
+    // --audio-quality is a bitrate selector meaningful only for lossy re-encodes.
+    // For lossless formats (flac/wav) it is silently ignored by yt-dlp (M21).
+    const lossless = o.audioFormat === 'flac' || o.audioFormat === 'wav'
+    args.push('-x', '--audio-format', o.audioFormat)
+    if (!lossless) args.push('--audio-quality', audioQuality(opts.quality))
     if (o.embedThumbnail) {
       args.push('--embed-thumbnail')
       if (o.cropThumbnail) args.push('--ppa', CROP_SQUARE_PPA)