docs: Audio workspace tab (Phase 1) — v1.3 changelog + README; drop orphaned transport spacer

README.md

@@ -33,6 +33,14 @@ All clips are exactly 8 seconds — the standard length for foley sound datasets
 - **Hardware encoding** — GPU-accelerated export via NVENC, VAAPI, QSV, AMF, or VideoToolbox
 - **Subject tracking** — auto-adjust crop center using YOLOv8 detection (optional)
 
+### Audio extraction & editing
+
+- **Extract audio area** — save an exact-length audio slice from the playhead (length steps by 1s, no upper cap)
+- **Output format** — WAV / MP3 / FLAC / M4A / OGG / OPUS, remembered between sessions
+- **Non-destructive edits** — fade in/out, EBU R128 normalize, and gain, applied via ffmpeg on extract (and audition)
+- **Waveform preview** — a read-only strip of the current area (↻ to refresh; decode length-capped so long areas don't stall)
+- **Audition** — Play/Stop the current area with the edits applied
+
 ### Audio scanning
 
 - **Embedding models** — WAV2VEC2 (base/large), HuBERT (base/large/xlarge), BEATs
@@ -43,6 +51,7 @@ All clips are exactly 8 seconds — the standard length for foley sound datasets
 - **Hard negatives** — mark false positives to refine training
 - **Model versioning** — timestamped backups with rollback support
 - **Scan export** — batch export from scan results with spread and minimum duration filtering
+- **Location** — scan controls live in the **Audio** tab's *Scan / Classify* pane (formerly the *Scan* tab)
 
 ### Scan results panel
 

main.py

@@ -4471,7 +4471,6 @@ class MainWindow(QMainWindow):
 
         # Extract audio area — an exact-length audio slice from the playhead,
         # saved via a Save As dialog (format follows the chosen extension).
-        transport_row.addSpacing(12)
         self._spn_audio_len = QDoubleSpinBox()
         # No practical upper cap — audio areas can be minutes long; ffmpeg stops
         # cleanly at end-of-file if the source is shorter. Arrows step by 1s;
@@ -4972,9 +4971,21 @@ class MainWindow(QMainWindow):
 
     # ── Changelog ────────────────────────────────────────────
 
-    APP_VERSION = "1.2"
+    APP_VERSION = "1.3"
     _SPLIT_HEADER_H = 22  # deck split-column header height (keep both deck spots in sync)
     CHANGELOG: list[tuple[str, list[str]]] = [
+        ("1.3", [
+            "<b>Audio workspace tab</b> — the <b>Scan</b> control-deck tab is "
+            "now <b>Audio</b>, a <code>QToolBox</code> with two panes. "
+            "<i>Extract &amp; Edit</i> has the audio-area length, an output "
+            "<b>format</b> picker (WAV / MP3 / FLAC / M4A / OGG / OPUS, "
+            "remembered), non-destructive <b>fade in/out, normalize, and "
+            "gain</b> applied on extract, a read-only <b>waveform</b> strip "
+            "(↻ to refresh), and <b>Play/Stop</b> audition of the current area "
+            "with the edits applied. <i>Scan / Classify</i> keeps the model, "
+            "threshold, and scan/auto/speech/review controls. The extract "
+            "length + button moved off the transport row into this tab.",
+        ]),
         ("1.2", [
             "<b>Per-tab export folder</b> — each file-list tab now remembers "
             "its own output folder; switching tabs follows that tab's folder. "