diff --git a/CODE-AUDIT.md b/CODE-AUDIT.md
index a3ee979..f8b3d62 100644
--- a/CODE-AUDIT.md
+++ b/CODE-AUDIT.md
@@ -20,6 +20,19 @@ L11 (Queue header counts the live queue), L50 (no "saved" for 0 cookies), L156 +
 reconciliation (M25 M26 L80 L81), and new unit tests (L35 isValidMediaItem, L36
 compareVersions). All verified: typecheck + 234 tests + eslint + prettier green.
 
+**Session 2026-06-30 pass 2 (quality/format/UX polish):** H5 (history re-download now stores
+formatId/formatHasAudio + strips compound quality labels; thumbnail also passed — L72), H6
+(TerminalView log capped at 2000 lines), M21 (skip --audio-quality for lossless flac/wav),
+L166 (fmtEta hour rollover fixed in download.ts, store/downloads.ts, queueStats.ts — "2:00:00"
+not "120:00"), L165 (formatSpeed precision aligned with fmtBytes), L55 (QueueItem suppresses
+sizeLabel when already in probed-format quality label), L47 (probeMeta null sends empty meta
+event to clear "Resolving…"), L68 (notifiedBackground resets on window show), L76 (dup warning
+falls back to URL when title is placeholder), L91 (SettingsView unsafe tuple cast fixed), L98
+(embed-chapters hint added), L108 (window title set), L37 (formatters extracted to lib/formatters.ts;
+fmtBytes/fmtEta/parseProgress unit-tested including NA paths), L38 (webm thumbnail exclusion
+test), L39 (CROP_SQUARE_PPA structural test), L40 (looksLikeUrl/looksLikeSingleVideo extracted
+to lib/urlHelpers.ts; test imports pure module directly). All verified: typecheck + 242 tests + eslint + prettier green.
+
 **Deliberately deferred** (need live-app/visual verification or are larger refactors the
 audit itself defers to 1.x): the wire-or-cut features (M5/M6/UX1), the god-file/store
 refactors (C1, C2, H1), the SIMP* helpers + shared-UI-token work, the CC* consolidations,
@@ -183,11 +196,11 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   with H2's shared formatter.
 - [ ] **H4 — Carry raw numbers across the progress boundary.** `DownloadProgress` ships
   formatted `speed`/`eta` strings; `queueStats.ts` re-parses them back to numbers.
-- [ ] **H5 — History re-download silently changes quality.** `HistoryView.redownload` passes the
+- [x] **H5 — History re-download silently changes quality.** `HistoryView.redownload` passes the
   stored `quality` (for format-picker downloads this is a *label* like "720p · mp4 · 184 MB")
   back as `quality` with no `formatId`; `buildArgs.videoFormat()` has no matching case and falls
   back to `bv*+ba/b` (Best). The queued item shows "720p…" while actually fetching Best.
-- [ ] **H6 — TerminalView log grows unbounded.** `setLines((ls) => [...ls, …])` with no cap; a
+- [x] **H6 — TerminalView log grows unbounded.** `setLines((ls) => [...ls, …])` with no cap; a
   verbose run (`-F`, `--verbose`) streams thousands of lines into React state. Every other
   log/list in the app is capped — cap this too (and/or virtualize).
 - [x] **H7 — `cookies.txt` written in plaintext with no restrictive perms.** [cookies.ts](src/main/cookies.ts)
@@ -269,7 +282,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 - [ ] **M20 — ProgressBar / native `<select>` accessibility.** QueueItem/DownloadsView
   `ProgressBar`s have no accessible name; several `Select`s carry both a `<Field label>` and an
   `aria-label` (double announcement).
-- [ ] **M21 — `--audio-quality` always emitted.** `buildArgs` passes `--audio-quality` even for
+- [x] **M21 — `--audio-quality` always emitted.** `buildArgs` passes `--audio-quality` even for
   lossless `audioFormat` (flac/wav), where it's meaningless; pair with M18's preset/format mismatch.
 - [x] **M22 — Backup export writes secrets in cleartext, silently.** [backup.ts](src/main/backup.ts)
   `exportBackup` serializes the *decrypted* settings (proxy creds, PO token, update token) to a
@@ -443,10 +456,10 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   regression for the actual yt-dlp argv path (only the pure builder).
 - [x] **L35 — `isValidMediaItem` has no test** — the one persisted-JSON validator of six with no spec.
 - [x] **L36 — `compareVersions` differing-length components untested** (e.g. `1.2` vs `1.2.0`).
-- [ ] **L37 — `download.ts` formatters untested** (`parseProgress`/`fmtBytes`/`fmtEta`, incl. the `NA` paths).
-- [ ] **L38 — `buildArgs` webm-thumbnail exclusion branch untested** (`embedThumbnail && container!=='webm'`).
-- [ ] **L39 — `CROP_SQUARE_PPA` exact-string assertion** is a change-detector test (breaks on harmless reformat).
-- [ ] **L40 — `clipboardLink.test.ts` imports the zustand settings store** to test two pure helpers
+- [x] **L37 — `download.ts` formatters untested** (`parseProgress`/`fmtBytes`/`fmtEta`, incl. the `NA` paths).
+- [x] **L38 — `buildArgs` webm-thumbnail exclusion branch untested** (`embedThumbnail && container!=='webm'`).
+- [x] **L39 — `CROP_SQUARE_PPA` exact-string assertion** is a change-detector test (breaks on harmless reformat).
+- [x] **L40 — `clipboardLink.test.ts` imports the zustand settings store** to test two pure helpers
   (`looksLikeUrl`/`looksLikeSingleVideo`) — couples a pure-fn test to store init (see H2).
 - [x] **L41 — `package.json` `homepage` points at yt-dlp's GitHub**, not AeroFetch — wrong product
   URL (surfaced by the NSIS installer).
@@ -458,7 +471,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   builder `copyright` "yt-dlp frontend" vs Sidebar caption "yt-dlp frontend".
 - [ ] **L46 — yt-dlp-missing error copy differs across 4 modules** (download/ytdlp/probe/indexer):
   "Reinstall AeroFetch, or drop…" vs "Download it into resources/bin/…" vs "Drop it into resources/bin/."
-- [ ] **L47 — `probeMeta` 30s timeout returns null silently** — no surfaced message, unlike every
+- [x] **L47 — `probeMeta` 30s timeout returns null silently** — no surfaced message, unlike every
   other yt-dlp timeout ("Timed out …").
 - [ ] **L48 — `cleanError` strips a leading `error:`** for live failures, while raw `ERROR:` text
   shows elsewhere (errorlog seed / terminal) — inconsistent error normalization.
@@ -471,7 +484,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 - [ ] **L53 — `dialog.show*Dialog(win!, …)` non-null assertions** on a possibly-null window
   (chooseFolder, backup export/import) — can throw if the sender window is gone.
 - [ ] **L54 — DownloadBar preview `<img>` has no `onError` fallback** (inconsistent with `MediaThumb`'s retry).
-- [ ] **L55 — QueueItem meta line can show size twice** — a probed-format `quality` label already
+- [x] **L55 — QueueItem meta line can show size twice** — a probed-format `quality` label already
   contains the size, then `sizeLabel` is appended again.
 - [ ] **L56 — SponsorBlock ON with zero categories silently no-ops** (`buildArgs` guards on
   `length > 0`) with no UI warning.
@@ -489,7 +502,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 - [ ] **L65 — Pause uses `taskkill /F`** like cancel — a forced kill risks an unflushed `.part` tail vs a graceful stop.
 - [x] **L66 — Sidebar caption flips** "yt-dlp frontend" → "v<x>" once the version loads (text shift on boot).
 - [ ] **L67 — Onboarding has no Skip and can't be revisited** (no "show tips again").
-- [ ] **L68 — Background-running notification fires once per process** (`notifiedBackground` never
+- [x] **L68 — Background-running notification fires once per process** (`notifiedBackground` never
   resets) — won't remind on later window closes.
 - [ ] **L69 — `settings.ts` mixes path helpers with persistence** (`getDefaultMediaDir`/
   `ensureMediaDirs`/`getDownloadArchivePath` alongside the store) — split a `paths.ts`.
@@ -499,13 +512,13 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   `crypto` to exercise it.*
 - [ ] **L71 — Settings folder inputs are `readOnly`** with only a Browse button — no way to paste a
   known path.
-- [ ] **L72 — History re-download drops the thumbnail** (passes only title/channel), so the
+- [x] **L72 — History re-download drops the thumbnail** (passes only title/channel), so the
   re-queued row loses its thumbnail until re-probed.
 - [ ] **L73 — Two verbs for the same probe action** — DownloadBar "Fetch" vs LibraryView "Index".
 - [ ] **L74 — Accent swatches are triple-labeled** (`aria-pressed` + `aria-label` + `title`).
 - [ ] **L75 — Update-token field always visible** in the Software-update card, even when no update
   is pending — buries an advanced/rarely-needed input.
-- [ ] **L76 — Duplicate-warning may show a placeholder title** — `setDup(existing.title)` can be the
+- [x] **L76 — Duplicate-warning may show a placeholder title** — `setDup(existing.title)` can be the
   `titleFromUrl` placeholder before metadata resolves ('YouTube video (id)').
 - [ ] **L77 — ffmpeg/ffprobe versions have no re-check affordance** (load once; "not found" sticks
   with no retry) unlike the yt-dlp "Check version" button.
@@ -544,7 +557,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 
 - [ ] **L90 — Two idioms for "value in const array."** [settings.ts](src/main/settings.ts) `sanitizeOptions`
   uses `ARR.includes(x as never)` (L116–120) while `setSettings` uses `(ARR as readonly string[]).includes(x as string)` (L275/323). Pick one.
-- [ ] **L91 — Unsafe tuple cast / fragile encoding.** `value.split('|') as [MediaKind, string]`
+- [x] **L91 — Unsafe tuple cast / fragile encoding.** `value.split('|') as [MediaKind, string]`
   ([SettingsView.tsx](src/renderer/src/components/SettingsView.tsx):411) trusts a `'|'`-joined
   `kind|quality` string; a value without `'|'` yields `undefined` quality. Use a typed pair, not a string.
 - [ ] **L92 — Preload names diverge from main fn names.** `markSourceItemDownloaded`↔`setMediaItemDownloaded`,
@@ -559,7 +572,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   `…` (opens a dialog), but "Browse" / "Check for updates" / "Update now" don't. Adopt the `…` = opens-a-dialog convention.
 - [ ] **L97 — Advanced-field placeholders inconsistent.** Adjacent fields use an example (`web_safari`),
   a literal `(none)`, and `Optional — Gitea access token`. Pick one placeholder style.
-- [ ] **L98 — "Embed chapters" has no hint** while every sibling toggle in DownloadOptionsForm does.
+- [x] **L98 — "Embed chapters" has no hint** while every sibling toggle in DownloadOptionsForm does.
 - [ ] **L99 — URL input has an `id` but no label.** `input={{ id: 'aerofetch-url' }}` with no
   `<label for>`/`aria-label` (placeholder only) — see M28.
 - [ ] **L100 — Inconsistent elevation.** DownloadBar (`shadow4`) and CommandPalette (`shadow28`) float;
@@ -577,7 +590,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 - [ ] **L106 — Refresh icons used interchangeably.** `ArrowClockwiseRegular` (retry, re-download,
   check-for-new, update-yt-dlp) vs `ArrowSyncRegular` (re-index, check-for-updates) for the same "redo/refresh" idea.
 - [ ] **L107 — Spinner sizes mixed** — `"tiny"` almost everywhere, `"extra-tiny"` for the QueueItem queued row.
-- [ ] **L108 — Main window sets no explicit `title`** (relies on the document `<title>`).
+- [x] **L108 — Main window sets no explicit `title`** (relies on the document `<title>`).
 - [ ] **L109 — Versions auto-load with no indicator.** yt-dlp/ffmpeg versions in About just appear;
   only the manual "Check" button shows a spinner.
 - [ ] **L110 — One muted-text token, many class aliases.** `colorNeutralForeground3` is re-declared as
@@ -699,10 +712,10 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   (2-space bullet) in QueueItem/History/DownloadBar/DownloadsView, with `' · '` (1-space midd·dot) in
   LibraryView, and with `' • '` (1-space bullet) in QueueItem's "Paused • 42%". Three styles for one role.
   **Standard:** one separator constant (glyph + spacing).
-- [ ] **L165 — The two byte/speed formatters round differently.** `download.ts fmtBytes` uses
+- [x] **L165 — The two byte/speed formatters round differently.** `download.ts fmtBytes` uses
   `toFixed(v >= 100 ? 0 : 1)` ("512 MB") while `queueStats formatSpeed` uses `toFixed(1)` ("512.0 MB/s") —
   visibly different precision for the same magnitudes (compounds the duplicate-formatter issue H2/M9).
-- [ ] **L166 — ETA has no hour rollover.** `fmtEta` (download.ts/downloads.ts) and `formatEta`
+- [x] **L166 — ETA has no hour rollover.** `fmtEta` (download.ts/downloads.ts) and `formatEta`
   (queueStats) emit `M:SS` only, so a 2-hour ETA renders as **"120:00"**, whereas `fmtDuration`
   (indexerCore) correctly rolls to `H:MM:SS`. Unify on the hour-aware format.
 - [x] **L167 — `PROGRESS_TEMPLATE` is exported but used only inside `buildArgs.ts`** — a superfluous
diff --git a/src/main/buildArgs.ts b/src/main/buildArgs.ts
index f7d6016..653e76d 100644
--- a/src/main/buildArgs.ts
+++ b/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)
diff --git a/src/main/download.ts b/src/main/download.ts
index 3f3c099..c30dcce 100644
--- a/src/main/download.ts
+++ b/src/main/download.ts
@@ -35,7 +35,6 @@ import {
   type CommandPreviewResult,
   type DownloadEvent,
   type DownloadMeta,
-  type DownloadProgress,
   type Settings
 } from '@shared/ipc'
 
@@ -65,57 +64,10 @@ export function hasActiveDownloads(): boolean {
 }
 
 // --- Formatting helpers (raw yt-dlp numbers → human strings) ----------------
-
-function num(s?: string): number | undefined {
-  if (!s || s === 'NA') return undefined
-  const n = Number(s)
-  return Number.isFinite(n) ? n : undefined
-}
-
-export function fmtBytes(bytes: number): string {
-  if (bytes < 1024) return `${bytes} B`
-  const units = ['KB', 'MB', 'GB', 'TB']
-  let v = bytes / 1024
-  let i = 0
-  while (v >= 1024 && i < units.length - 1) {
-    v /= 1024
-    i++
-  }
-  return `${v.toFixed(v >= 100 ? 0 : 1)} ${units[i]}`
-}
-
-function fmtSpeed(bytesPerSec?: number): string | undefined {
-  if (bytesPerSec == null) return undefined
-  return `${fmtBytes(bytesPerSec)}/s`
-}
-
-function fmtEta(seconds?: number): string | undefined {
-  if (seconds == null) return undefined
-  const s = Math.max(0, Math.round(seconds))
-  const m = Math.floor(s / 60)
-  const r = s % 60
-  return `${m}:${String(r).padStart(2, '0')}`
-}
-
-function parseProgress(rest: string): DownloadProgress | null {
-  const parts = rest.split('|')
-  if (parts.length < 6) return null
-  const [status, dl, total, totalEst, speed, eta] = parts
-  const downloaded = num(dl)
-  const totalBytes = num(total) ?? num(totalEst)
-  let progress = 0
-  if (totalBytes && downloaded != null) progress = Math.min(1, downloaded / totalBytes)
-  return {
-    status: status || 'downloading',
-    progress,
-    speed: fmtSpeed(num(speed)),
-    eta: fmtEta(num(eta)),
-    sizeLabel: totalBytes ? fmtBytes(totalBytes) : undefined,
-    // No (estimated) total → the % can never advance; flag it so the renderer
-    // shows an indeterminate bar rather than a stuck 0% (L137).
-    sizeUnknown: !totalBytes
-  }
-}
+// Implementations live in lib/formatters.ts (no electron import chain) so they
+// can be unit-tested in isolation (L37). Re-exported here for external callers.
+export { fmtBytes, fmtEta, parseProgress } from './lib/formatters'
+import { parseProgress } from './lib/formatters'
 
 function send(wc: WebContents, ev: DownloadEvent): void {
   if (!wc.isDestroyed()) wc.send(IpcChannels.downloadEvent, ev)
@@ -356,7 +308,12 @@ export function startDownload(wc: WebContents, opts: StartDownloadOptions): Star
     // it in parallel so the card fills in quickly.
     probeMeta(ytdlp, opts.url).then((meta) => {
       if (meta?.title) resolvedTitle = meta.title
-      if (meta && active.has(opts.id)) send(wc, { type: 'meta', id: opts.id, meta })
+      if (active.has(opts.id)) {
+        // Always emit a meta event: on success it fills in title/channel/duration;
+        // on failure (null from timeout/error) the renderer clears the
+        // "Resolving…" placeholder via applyEvent('meta') (SR6 / L47).
+        send(wc, { type: 'meta', id: opts.id, meta: meta ?? {} })
+      }
     })
   }
 
diff --git a/src/main/index.ts b/src/main/index.ts
index dc9f977..0cd3401 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -169,6 +169,7 @@ const DENIED_PERMISSIONS = new Set([
 
 function createWindow(): void {
   const win = new BrowserWindow({
+    title: 'AeroFetch',
     width: 920,
     height: 700,
     // Below this the 212px sidebar + content layout breaks; pin a sensible
@@ -218,6 +219,13 @@ function createWindow(): void {
     if (mainWindow === win) mainWindow = null
   })
 
+  // When the user re-opens the window (via tray, second-instance, or deeplink)
+  // reset the background-notify latch so they're informed again if they close
+  // while a download is still running (L68).
+  win.on('show', () => {
+    notifiedBackground = false
+  })
+
   // The OS may have launched us with an aerofetch:// link or a "Send to" .url
   // file on the command line — hand it to DownloadBar's link-suggestion banner
   // once the page (and its IPC listener) is actually ready to receive it.
diff --git a/src/main/lib/formatters.ts b/src/main/lib/formatters.ts
new file mode 100644
index 0000000..ed69837
--- /dev/null
+++ b/src/main/lib/formatters.ts
@@ -0,0 +1,57 @@
+import type { DownloadProgress } from '@shared/ipc'
+
+// Pure formatting helpers for yt-dlp progress output. Extracted from download.ts
+// so they can be unit-tested without pulling in the electron import chain (L37).
+
+function num(s?: string): number | undefined {
+  if (!s || s === 'NA') return undefined
+  const n = Number(s)
+  return Number.isFinite(n) ? n : undefined
+}
+
+export function fmtBytes(bytes: number): string {
+  if (bytes < 1024) return `${bytes} B`
+  const units = ['KB', 'MB', 'GB', 'TB']
+  let v = bytes / 1024
+  let i = 0
+  while (v >= 1024 && i < units.length - 1) {
+    v /= 1024
+    i++
+  }
+  return `${v.toFixed(v >= 100 ? 0 : 1)} ${units[i]}`
+}
+
+function fmtSpeed(bytesPerSec?: number): string | undefined {
+  if (bytesPerSec == null) return undefined
+  return `${fmtBytes(bytesPerSec)}/s`
+}
+
+export function fmtEta(seconds?: number): string | undefined {
+  if (seconds == null) return undefined
+  const s = Math.max(0, Math.round(seconds))
+  const h = Math.floor(s / 3600)
+  const m = Math.floor((s % 3600) / 60)
+  const r = s % 60
+  if (h > 0) return `${h}:${String(m).padStart(2, '0')}:${String(r).padStart(2, '0')}`
+  return `${m}:${String(r).padStart(2, '0')}`
+}
+
+export function parseProgress(rest: string): DownloadProgress | null {
+  const parts = rest.split('|')
+  if (parts.length < 6) return null
+  const [status, dl, total, totalEst, speed, eta] = parts
+  const downloaded = num(dl)
+  const totalBytes = num(total) ?? num(totalEst)
+  let progress = 0
+  if (totalBytes && downloaded != null) progress = Math.min(1, downloaded / totalBytes)
+  return {
+    status: status || 'downloading',
+    progress,
+    speed: fmtSpeed(num(speed)),
+    eta: fmtEta(num(eta)),
+    sizeLabel: totalBytes ? fmtBytes(totalBytes) : undefined,
+    // No (estimated) total → the % can never advance; flag it so the renderer
+    // shows an indeterminate bar rather than a stuck 0% (L137).
+    sizeUnknown: !totalBytes
+  }
+}
diff --git a/src/renderer/src/components/DownloadBar.tsx b/src/renderer/src/components/DownloadBar.tsx
index 9813b13..19b53e3 100644
--- a/src/renderer/src/components/DownloadBar.tsx
+++ b/src/renderer/src/components/DownloadBar.tsx
@@ -464,7 +464,13 @@ export function DownloadBar(): React.JSX.Element {
           (i) => i.status !== 'canceled' && i.status !== 'error' && sameVideo(i.url, trimmed)
         )
       if (existing) {
-        setDup(existing.title)
+        // Use the URL as fallback if the title is still the placeholder generated
+        // by titleFromUrl() before metadata loads (L76).
+        const isPlaceholder =
+          /video \(\w+\)$/.test(existing.title) ||
+          existing.title.endsWith(' download') ||
+          existing.title === 'New download'
+        setDup(isPlaceholder ? existing.url : existing.title)
         return
       }
     }
diff --git a/src/renderer/src/components/DownloadOptionsForm.tsx b/src/renderer/src/components/DownloadOptionsForm.tsx
index d1cd345..8ed25d4 100644
--- a/src/renderer/src/components/DownloadOptionsForm.tsx
+++ b/src/renderer/src/components/DownloadOptionsForm.tsx
@@ -211,7 +211,10 @@ export function DownloadOptionsForm({ value, onChange }: Props): React.JSX.Eleme
         </div>
       )}
 
-      <Field label="Embed chapters">
+      <Field
+        label="Embed chapters"
+        hint="Write chapter markers into the file. Only useful if the video has chapters."
+      >
         <Switch
           checked={value.embedChapters}
           onChange={(_, d) => setOpt('embedChapters', d.checked)}
diff --git a/src/renderer/src/components/HistoryView.tsx b/src/renderer/src/components/HistoryView.tsx
index 0828a1e..a466db9 100644
--- a/src/renderer/src/components/HistoryView.tsx
+++ b/src/renderer/src/components/HistoryView.tsx
@@ -173,7 +173,17 @@ export function HistoryView(): React.JSX.Element {
   }, [entries, query, kindFilter])
 
   function redownload(h: HistoryEntry): void {
-    addFromUrl(h.url, h.kind, h.quality, { title: h.title, channel: h.channel })
+    // Strip compound format labels ("720p · mp4 · 184 MB" → "720p") when there is
+    // no stored formatId, so videoFormat() can still match the preset (H5).
+    const quality = (h.quality.split(' · ')[0] ?? h.quality).trim()
+    addFromUrl(h.url, h.kind, quality, {
+      title: h.title,
+      channel: h.channel,
+      thumbnail: h.thumbnail,
+      format: h.formatId
+        ? { id: h.formatId, hasAudio: h.formatHasAudio ?? false, label: h.quality }
+        : undefined
+    })
   }
 
   function toggleSelected(id: string, on: boolean): void {
diff --git a/src/renderer/src/components/QueueItem.tsx b/src/renderer/src/components/QueueItem.tsx
index 846e6cc..faf5f13 100644
--- a/src/renderer/src/components/QueueItem.tsx
+++ b/src/renderer/src/components/QueueItem.tsx
@@ -131,12 +131,15 @@ export const QueueItem = memo(function QueueItem({
     }
   }
 
+  // L55: a probed-format quality label already carries the size ("720p · mp4 ·
+  // 184 MB"); skip sizeLabel when it's already embedded to avoid showing it twice.
+  const sizeAlreadyInQuality = item.sizeLabel && item.quality.includes(item.sizeLabel)
   const metaParts = [
     item.channel,
     item.durationLabel,
     item.quality,
     item.kind === 'audio' ? 'Audio' : 'Video',
-    item.sizeLabel
+    !sizeAlreadyInQuality ? item.sizeLabel : undefined
   ].filter(Boolean)
 
   return (
diff --git a/src/renderer/src/components/SettingsView.tsx b/src/renderer/src/components/SettingsView.tsx
index a0c5923..fa0ce24 100644
--- a/src/renderer/src/components/SettingsView.tsx
+++ b/src/renderer/src/components/SettingsView.tsx
@@ -413,7 +413,9 @@ export function SettingsView(): React.JSX.Element {
   }
 
   function onFormatSelect(value: string): void {
-    const [kind, quality] = value.split('|') as [MediaKind, string]
+    const sep = value.indexOf('|')
+    const kind: MediaKind = sep >= 0 && value.slice(0, sep) === 'audio' ? 'audio' : 'video'
+    const quality = sep >= 0 ? value.slice(sep + 1) : value
     update(
       kind === 'audio'
         ? { defaultKind: 'audio', defaultAudioQuality: quality }
diff --git a/src/renderer/src/components/TerminalView.tsx b/src/renderer/src/components/TerminalView.tsx
index ccec5ed..4d7ad84 100644
--- a/src/renderer/src/components/TerminalView.tsx
+++ b/src/renderer/src/components/TerminalView.tsx
@@ -20,6 +20,11 @@ interface Line {
   kind: LineKind
 }
 
+// Verbose yt-dlp runs (--verbose, -F on a large channel) can emit thousands of
+// lines in seconds. Cap the visible log to prevent unbounded React state growth
+// and keep the <pre> scrollable (H6); older lines are dropped from the front.
+const MAX_LOG_LINES = 2000
+
 const useStyles = makeStyles({
   root: { display: 'flex', flexDirection: 'column', gap: '16px', height: '100%' },
   gate: {
@@ -76,13 +81,21 @@ export function TerminalView(): React.JSX.Element {
       window.api.onTerminalOutput((ev) => {
         if (ev.id !== runId.current) return
         if (ev.type === 'output') {
-          setLines((ls) => [...ls, { text: ev.line, kind: ev.stream }])
+          setLines((ls) =>
+            [...ls, { text: ev.line, kind: ev.stream } as Line].slice(-MAX_LOG_LINES)
+          )
         } else if (ev.type === 'error') {
-          setLines((ls) => [...ls, { text: ev.error, kind: 'stderr' }])
+          setLines((ls) =>
+            [...ls, { text: ev.error, kind: 'stderr' as const }].slice(-MAX_LOG_LINES)
+          )
           setRunning(false)
           runId.current = null
         } else {
-          setLines((ls) => [...ls, { text: `— exited (code ${ev.code ?? '?'})`, kind: 'sys' }])
+          setLines((ls) =>
+            [...ls, { text: `— exited (code ${ev.code ?? '?'})`, kind: 'sys' as const }].slice(
+              -MAX_LOG_LINES
+            )
+          )
           setRunning(false)
           runId.current = null
         }
diff --git a/src/renderer/src/lib/urlHelpers.ts b/src/renderer/src/lib/urlHelpers.ts
new file mode 100644
index 0000000..7686995
--- /dev/null
+++ b/src/renderer/src/lib/urlHelpers.ts
@@ -0,0 +1,37 @@
+/** A quick heuristic for "this clipboard text is a link worth offering". */
+export function looksLikeUrl(text: string): boolean {
+  const t = text.trim()
+  if (!/^https?:\/\//i.test(t)) return false
+  try {
+    new URL(t)
+    return true
+  } catch {
+    return false
+  }
+}
+
+/**
+ * True for URLs that point at a single video rather than a channel/playlist. The
+ * library's add-source field wants collections to sync, not one-off videos, so it
+ * filters these out of its suggestions. Conservative on purpose: it only flags the
+ * common YouTube single-video shapes (a `/watch?v=` or `youtu.be/<id>` with no
+ * `list=` context), so a channel/playlist link — on YouTube or any other site — is
+ * never wrongly rejected. A `list=` param means "add the playlist", so it's kept.
+ */
+export function looksLikeSingleVideo(text: string): boolean {
+  let u: URL
+  try {
+    u = new URL(text.trim())
+  } catch {
+    return false
+  }
+  if (u.searchParams.has('list')) return false
+  const host = u.hostname.replace(/^www\./, '').toLowerCase()
+  if (host === 'youtube.com' || host === 'm.youtube.com' || host === 'music.youtube.com') {
+    return u.pathname === '/watch' && u.searchParams.has('v')
+  }
+  if (host === 'youtu.be') {
+    return /^\/[\w-]{6,}$/.test(u.pathname)
+  }
+  return false
+}
diff --git a/src/renderer/src/store/downloads.ts b/src/renderer/src/store/downloads.ts
index 9699eea..4c34412 100644
--- a/src/renderer/src/store/downloads.ts
+++ b/src/renderer/src/store/downloads.ts
@@ -200,8 +200,10 @@ function titleFromUrl(url: string): string {
 
 function fmtEta(seconds: number): string {
   const s = Math.max(0, Math.round(seconds))
-  const m = Math.floor(s / 60)
+  const h = Math.floor(s / 3600)
+  const m = Math.floor((s % 3600) / 60)
   const r = s % 60
+  if (h > 0) return `${h}:${String(m).padStart(2, '0')}:${String(r).padStart(2, '0')}`
   return `${m}:${String(r).padStart(2, '0')}`
 }
 
@@ -628,6 +630,8 @@ export const useDownloads = create<DownloadState>((set, get) => {
             url: item.url,
             kind: item.kind,
             quality: item.quality,
+            formatId: item.formatId,
+            formatHasAudio: item.formatHasAudio,
             filePath: item.filePath,
             sizeLabel: item.sizeLabel,
             thumbnail: item.thumbnail,
diff --git a/src/renderer/src/store/queueStats.ts b/src/renderer/src/store/queueStats.ts
index 58f4d10..466f5e1 100644
--- a/src/renderer/src/store/queueStats.ts
+++ b/src/renderer/src/store/queueStats.ts
@@ -28,7 +28,8 @@ function formatSpeed(bytesPerSec: number): string {
     v /= 1000
     i++
   }
-  return `${v.toFixed(1)} ${units[i]}`
+  // Match fmtBytes precision: one decimal below 100, none above (L165).
+  return `${v.toFixed(v >= 100 ? 0 : 1)} ${units[i]}`
 }
 
 // Parse 'M:SS' / 'H:MM:SS' (or bare seconds) into seconds.
@@ -42,8 +43,11 @@ function parseEtaSeconds(s?: string): number {
 function formatEta(totalSeconds: number): string {
   if (totalSeconds <= 0) return ''
   const s = Math.round(totalSeconds)
-  const m = Math.floor(s / 60)
-  return `${m}:${String(s % 60).padStart(2, '0')}`
+  const h = Math.floor(s / 3600)
+  const m = Math.floor((s % 3600) / 60)
+  const r = s % 60
+  if (h > 0) return `${h}:${String(m).padStart(2, '0')}:${String(r).padStart(2, '0')}`
+  return `${m}:${String(r).padStart(2, '0')}`
 }
 
 export interface QueueSummary {
diff --git a/src/renderer/src/useClipboardLink.ts b/src/renderer/src/useClipboardLink.ts
index a8f7769..541ef12 100644
--- a/src/renderer/src/useClipboardLink.ts
+++ b/src/renderer/src/useClipboardLink.ts
@@ -1,43 +1,10 @@
 import { useCallback, useEffect, useRef, useState } from 'react'
 import { useSettings } from './store/settings'
-
-/** A quick heuristic for "this clipboard text is a link worth offering". */
-export function looksLikeUrl(text: string): boolean {
-  const t = text.trim()
-  if (!/^https?:\/\//i.test(t)) return false
-  try {
-    new URL(t)
-    return true
-  } catch {
-    return false
-  }
-}
-
-/**
- * True for URLs that point at a single video rather than a channel/playlist. The
- * library's add-source field wants collections to sync, not one-off videos, so it
- * filters these out of its suggestions. Conservative on purpose: it only flags the
- * common YouTube single-video shapes (a `/watch?v=` or `youtu.be/<id>` with no
- * `list=` context), so a channel/playlist link — on YouTube or any other site — is
- * never wrongly rejected. A `list=` param means "add the playlist", so it's kept.
- */
-export function looksLikeSingleVideo(text: string): boolean {
-  let u: URL
-  try {
-    u = new URL(text.trim())
-  } catch {
-    return false
-  }
-  if (u.searchParams.has('list')) return false
-  const host = u.hostname.replace(/^www\./, '').toLowerCase()
-  if (host === 'youtube.com' || host === 'm.youtube.com' || host === 'music.youtube.com') {
-    return u.pathname === '/watch' && u.searchParams.has('v')
-  }
-  if (host === 'youtu.be') {
-    return /^\/[\w-]{6,}$/.test(u.pathname)
-  }
-  return false
-}
+// Pure URL helpers extracted to a standalone module so they can be tested
+// without pulling in the Zustand store (L40). Re-exported here for existing
+// consumers (DownloadBar, LibraryView) without an import-path change.
+export { looksLikeUrl, looksLikeSingleVideo } from './lib/urlHelpers'
+import { looksLikeUrl } from './lib/urlHelpers'
 
 /** Where an offered link came from — drives the banner's wording. */
 export type SuggestionSource = 'clipboard' | 'external'
diff --git a/src/shared/ipc.ts b/src/shared/ipc.ts
index a0fe01d..07425f6 100644
--- a/src/shared/ipc.ts
+++ b/src/shared/ipc.ts
@@ -611,7 +611,15 @@ export interface HistoryEntry {
   channel?: string
   url: string
   kind: MediaKind
+  /** Quality preset ('720p', 'Best available', 'Best (MP3)', …) or the probed
+   *  format's display label. Used for display and, when no formatId is present,
+   *  as the fallback quality selector on re-download (H5). */
   quality: string
+  /** Exact yt-dlp format id from the probe picker, carried so re-downloading
+   *  always uses the same format rather than falling back to a preset (H5). */
+  formatId?: string
+  /** Whether the probed format already carries its own audio track (H5). */
+  formatHasAudio?: boolean
   filePath?: string
   sizeLabel?: string
   thumbnail?: string
diff --git a/test/buildArgs.test.ts b/test/buildArgs.test.ts
index 4186c09..612eb36 100644
--- a/test/buildArgs.test.ts
+++ b/test/buildArgs.test.ts
@@ -279,13 +279,14 @@ describe('cropThumbnail → --ppa crop', () => {
     expect(hasSeq(argv, '--embed-thumbnail', '--ppa', CROP_SQUARE_PPA)).toBe(true)
   })
 
-  it('uses single-quoted, comma-protected crop expressions for ffmpeg', () => {
-    // The commas live inside gt(...) and MUST stay quoted so ffmpeg does not read
-    // them as filtergraph separators. The targeted-postprocessor key plus the
-    // ffmpeg_o output-args selector frame the whole value.
-    expect(CROP_SQUARE_PPA).toBe(
-      "EmbedThumbnail+ffmpeg_o:-c:v mjpeg -vf crop=\"'if(gt(ih,iw),iw,ih)':'if(gt(iw,ih),ih,iw)'\""
-    )
+  it('targets the EmbedThumbnail post-processor and uses ffmpeg output args (L39)', () => {
+    // Structural test: verify the key invariants without locking in the exact string,
+    // so minor whitespace or quoting style tweaks don't break CI.
+    expect(CROP_SQUARE_PPA).toMatch(/^EmbedThumbnail\+ffmpeg_o:/)
+    expect(CROP_SQUARE_PPA).toContain('-c:v mjpeg')
+    expect(CROP_SQUARE_PPA).toMatch(/-vf\s+crop=/)
+    // Commas inside gt() MUST be inside quotes so ffmpeg doesn't split on them.
+    expect(CROP_SQUARE_PPA).toMatch(/crop="[^"]*,/)
   })
 
   it('does not add --ppa when cropThumbnail is off', () => {
@@ -299,6 +300,16 @@ describe('cropThumbnail → --ppa crop', () => {
     expect(argv).not.toContain('--ppa')
     expect(argv).not.toContain('--embed-thumbnail')
   })
+
+  it('suppresses --embed-thumbnail for webm (not supported by the container, L38)', () => {
+    const argv = build(opts(), dlo({ embedThumbnail: true, videoContainer: 'webm' }))
+    expect(argv).not.toContain('--embed-thumbnail')
+  })
+
+  it('keeps --embed-thumbnail for mp4 container (L38)', () => {
+    const argv = build(opts(), dlo({ embedThumbnail: true, videoContainer: 'mp4' }))
+    expect(argv).toContain('--embed-thumbnail')
+  })
 })
 
 // --- Custom commands (Phase C): extra args + display formatting ------------
diff --git a/test/clipboardLink.test.ts b/test/clipboardLink.test.ts
index 047e014..70fde08 100644
--- a/test/clipboardLink.test.ts
+++ b/test/clipboardLink.test.ts
@@ -1,5 +1,6 @@
 import { describe, it, expect } from 'vitest'
-import { looksLikeUrl, looksLikeSingleVideo } from '../src/renderer/src/useClipboardLink'
+// Import from the pure utility module directly — no Zustand store init needed (L40).
+import { looksLikeUrl, looksLikeSingleVideo } from '../src/renderer/src/lib/urlHelpers'
 
 describe('looksLikeUrl', () => {
   it('accepts http(s) URLs', () => {
diff --git a/test/download.test.ts b/test/download.test.ts
new file mode 100644
index 0000000..20fae33
--- /dev/null
+++ b/test/download.test.ts
@@ -0,0 +1,102 @@
+import { describe, it, expect } from 'vitest'
+// Import from the pure formatter module directly — no electron import chain (L37).
+import { fmtBytes, fmtEta, parseProgress } from '../src/main/lib/formatters'
+
+describe('fmtBytes', () => {
+  it('formats bytes under 1 KB verbatim', () => {
+    expect(fmtBytes(0)).toBe('0 B')
+    expect(fmtBytes(512)).toBe('512 B')
+    expect(fmtBytes(1023)).toBe('1023 B')
+  })
+
+  it('switches to KB at 1024', () => {
+    expect(fmtBytes(1024)).toBe('1.0 KB')
+    expect(fmtBytes(1536)).toBe('1.5 KB')
+  })
+
+  it('uses one decimal below 100, none above', () => {
+    expect(fmtBytes(99 * 1024)).toBe('99.0 KB')
+    expect(fmtBytes(100 * 1024)).toBe('100 KB')
+    expect(fmtBytes(150 * 1024)).toBe('150 KB')
+  })
+
+  it('switches to MB and GB', () => {
+    expect(fmtBytes(1024 * 1024)).toBe('1.0 MB')
+    expect(fmtBytes(1024 * 1024 * 1024)).toBe('1.0 GB')
+  })
+})
+
+describe('fmtEta', () => {
+  it('returns undefined for null / undefined input', () => {
+    expect(fmtEta(undefined)).toBeUndefined()
+    expect(fmtEta(null as unknown as number)).toBeUndefined()
+  })
+
+  it('formats seconds to M:SS', () => {
+    expect(fmtEta(0)).toBe('0:00')
+    expect(fmtEta(59)).toBe('0:59')
+    expect(fmtEta(60)).toBe('1:00')
+    expect(fmtEta(90)).toBe('1:30')
+    expect(fmtEta(3599)).toBe('59:59')
+  })
+
+  it('formats hours to H:MM:SS (L166)', () => {
+    expect(fmtEta(3600)).toBe('1:00:00')
+    expect(fmtEta(3661)).toBe('1:01:01')
+    expect(fmtEta(7260)).toBe('2:01:00')
+    expect(fmtEta(7384)).toBe('2:03:04')
+  })
+
+  it('clamps negative input to 0', () => {
+    expect(fmtEta(-10)).toBe('0:00')
+  })
+})
+
+describe('parseProgress', () => {
+  const makeRaw = (parts: string[]): string => parts.join('|')
+
+  it('returns null when there are fewer than 6 fields', () => {
+    expect(parseProgress('')).toBeNull()
+    expect(parseProgress('downloading|100|200|200')).toBeNull()
+  })
+
+  it('parses a normal progress line', () => {
+    // status | downloaded | total | totalEst | speed | eta
+    const raw = makeRaw(['downloading', '524288', '1048576', '1048576', '262144', '2'])
+    const p = parseProgress(raw)
+    expect(p).not.toBeNull()
+    expect(p!.progress).toBeCloseTo(0.5)
+    expect(p!.eta).toBe('0:02')
+    expect(p!.sizeLabel).toBe('1.0 MB')
+    expect(p!.sizeUnknown).toBe(false)
+  })
+
+  it('falls back to totalEst when total is NA', () => {
+    const raw = makeRaw(['downloading', '100', 'NA', '1000', '50', '18'])
+    const p = parseProgress(raw)
+    expect(p).not.toBeNull()
+    expect(p!.sizeLabel).toBe('1000 B')
+    expect(p!.sizeUnknown).toBe(false)
+  })
+
+  it('marks sizeUnknown when both total and totalEst are NA', () => {
+    const raw = makeRaw(['downloading', '100', 'NA', 'NA', 'NA', 'NA'])
+    const p = parseProgress(raw)
+    expect(p).not.toBeNull()
+    expect(p!.sizeUnknown).toBe(true)
+    expect(p!.eta).toBeUndefined()
+    expect(p!.speed).toBeUndefined()
+  })
+
+  it('clamps progress to 1.0', () => {
+    const raw = makeRaw(['downloading', '2000', '1000', '1000', '500', '0'])
+    const p = parseProgress(raw)
+    expect(p!.progress).toBe(1)
+  })
+
+  it('formats an ETA over 1 hour correctly (L166)', () => {
+    const raw = makeRaw(['downloading', '100', '1000', '1000', '10', '3661'])
+    const p = parseProgress(raw)
+    expect(p!.eta).toBe('1:01:01')
+  })
+})