Bump to v1.4.0: recording-settings dialog cleanup, menu mnemonics

Ships the dialog reorganisation and mnemonic adjustments from
commit 45b709d. No wire-format or audio-pipeline changes — v1.3 and
v1.4 peers interoperate.

About dialog gets a v1.4 release-notes block; csproj Version
property bumped 1.3.0 → 1.4.0; RELEASE_NOTES.md rewritten with the
v1.4 highlights and a one-paragraph upgrading-from-v1.3 note (clean
auto-update via Help → Check for updates is now expected to work on
Dropbox-installed copies since v1.3's helper hardening took effect).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

RELEASE_NOTES.md

@@ -1,37 +1,37 @@
-# RemSound v1.3
+# RemSound v1.4
 
-Updater hardening for Dropbox-installed copies. The wire format, audio pipeline, and recording feature are unchanged from v1.2.
+Recording-settings dialog cleanup and a few mnemonic adjustments. No wire-format or audio-pipeline changes — v1.4 and v1.3 peers interoperate.
 
-## What's fixed
+## Highlights
 
-The v1.2 self-updater silently failed on installs inside Dropbox-synced folders. The cause: Dropbox held write locks on the existing `RemSound.exe` / DLLs during the brief window between the parent process exiting and the helper script copying the new files in. Robocopy gave up after 5 seconds, and the helper unconditionally relaunched the old binary regardless — so users saw the same version they started with after pressing **Yes** on the install prompt.
+### Recording settings dialog reorganised
 
-## What's new
+- **Channel mode** is now its own dedicated listbox (**Alt+C**) instead of being folded into every attribute row. The per-format attribute lists shrink correspondingly:
+    - **WAV** — 6 rows → **3** (16-bit PCM / 24-bit PCM / 32-bit float)
+    - **MP3** — 8 rows → **4** (128 / 192 / 256 / 320 kbps CBR)
+    - **OGG-Opus** — 8 rows → **4** (96 / 128 / 192 / 256 kbps VBR)
+    - **FLAC** — 4 rows → **2** (16-bit / 24-bit)
+- **FLAC compression level** (0..8) now selectable in its own listbox (**Alt+L**). Previously hard-fixed at the libFLAC default of 5. The list is only shown when the file format is FLAC, with friendly tags on the endpoints (`0 — fastest encode, biggest file`, `5 — default (libFLAC reference)`, `8 — slowest encode, smallest file`). All levels produce bit-identical lossless audio — it's a pure encode-time vs file-size trade-off.
 
-- **Robocopy retries bumped to 60 seconds per file** (was 5). Dropbox lock release happens reliably within that window in practice.
-- **Helper checks robocopy's exit code.** On a true failure (exit code 8+), the helper writes `update-failed.txt` next to `RemSound.exe` with the cause and recovery steps, and does **not** relaunch the old binary. Earlier versions silently relaunched the unmodified old binary, hiding the failure.
-- **Helper writes a step-by-step log** to `_update-helper.log` in the install folder. If a future update goes wrong this is the trace.
-- **Stale failure markers are cleared** at the start of every new update attempt, so a successful run leaves the install folder clean.
+### Record menu mnemonics
 
-## Already on v1.0, v1.1, or v1.2 and inside a Dropbox folder? Read this first
+- **Start / Stop recording** is now `Alt+O, R` (was `Alt+O, S`). Matches the `Ctrl+R` global toggle so the same letter does the same job from either entry point. The underline stays on a literal *R* as the label flips between "Sta**r**t recording" and "Stop **r**ecording".
+- **Recording settings** is now `Alt+O, S` (was `Alt+O, T`). Reads more naturally now that the *R* slot is freed.
+- **Open folder** (`Alt+O, O`) and **Change folder** (`Alt+O, C`) unchanged.
 
-**The auto-updater in earlier versions won't reliably take you to v1.3** if you installed RemSound inside a Dropbox-synced (or other file-sync) folder. That's the bug v1.3 fixes — but the fix is in the *running* version's helper script, not in the downloaded zip, so your old version can't use it. The pre-v1.3 helper retries for only 5 seconds before silently giving up and relaunching the old binary; your About dialog will keep saying the old version even after pressing **Yes** on the update prompt.
+### Dialog mnemonic adjustment
 
-Manual install fixes it permanently:
+- The **Cancel** button in the Recording settings dialog now uses **Alt+N** (`Ca&ncel`) rather than the conventional Alt+C, so the **Channels** listbox can take Alt+C as its natural letter. Esc still dismisses the dialog the way it always has.
 
-1. Quit RemSound (right-click the tray icon → Exit, or just close the window).
-2. Wait ~30 seconds for Dropbox to settle.
-3. Download `RemSound-v1.3.zip` below.
-4. Extract it on top of your existing install folder (right-click → Extract All, point at your RemSound folder, accept "replace files"). Or unzip somewhere else first and copy the files across.
-5. Launch RemSound.exe. About should now report v1.3.0.
+## Install
 
-From v1.3 onward, **Check for updates** uses the hardened helper (60-second retry window, failure markers, no silent rollback), so you only have to do this manual step once.
-
-## Install (clean machine)
-
-1. Download `RemSound-v1.3.zip` from this release.
+1. Download `RemSound-v1.4.zip` from this release.
 2. Extract somewhere with write permission (e.g. `C:\RemSound\`, `Documents\RemSound\`, etc.). Avoid `Program Files` unless you grant write permission so the self-updater can replace files in place.
 3. Run `RemSound.exe`. Allow on private networks when Windows Firewall prompts.
 4. Press F1 (or use the Help menu) for the user manual.
 
 Requires the .NET 10 Desktop Runtime. If it's missing, Windows offers to fetch it on first launch.
+
+## Upgrading from v1.3 inside a Dropbox folder
+
+Should work cleanly via Help → Check for updates. v1.3 introduced the hardened helper (60-second retry window, exit-code check, no silent rollback) so the Dropbox-lock window is no longer a problem. If you're on v1.0/v1.1/v1.2 in a Dropbox folder, see the v1.3 release notes for the one-time manual install steps — once on v1.3 or later, future auto-updates are reliable.