Release v4.5: import shortcuts on pre-4.4 upgrade + clearer shortcuts dialog

- Pre-v4.4 upgraders are offered a one-time dialog to copy their keyboard shortcuts
  from one of their profiles (still readable in the profile files) instead of being
  reset. Users who already went through v4.4's reset are deliberately NOT re-offered
  (gated on KeyboardShortcutsGlobalNoticeShown). New KeyboardShortcutImportDialog +
  AppConfig.KeyboardShortcutsImportOffered + MainFormHotkeyController.ReloadAndReRegisterAll.
- Keyboard shortcuts dialog: new "Clear this shortcut" button; Delete inside the
  capture box leaves a shortcut unassigned.
- Relabelled the three RemSound-app remote rows to "Send remote RemSound volume/..."
  to distinguish them from the Windows-global ones.
- Manual (readme.html + MANUAL.md), About changelog, RELEASE_NOTES updated; version 4.5.

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

RELEASE_NOTES.md

@@ -1,25 +1,34 @@
-# RemSound v4.4
+# RemSound v4.5
 
-Keyboard shortcuts are now shared across all your profiles.
+Keyboard shortcuts get easier to manage — and people upgrading from before 4.4 no longer lose theirs.
 
-Until now, shortcuts were saved separately inside each profile — so a shortcut you set on one profile wouldn't work on another, and switching profiles could make a shortcut seem to disappear. From this version they're one set shared by the whole app: set a shortcut once and it works on every profile, and stays put when you switch. This is what people asked for.
+## Bring your shortcuts across when you upgrade
 
-**Because of this change, shortcuts have gone back to their defaults.** If you'd set up any of your own, please set them again in Options → Keyboard shortcuts (Ctrl+K) — you only need to do it once, and a reminder shows the first time you run this version. (Brand-new installs aren't affected.)
+In version 4.4, keyboard shortcuts moved from being saved per-profile to one shared set for the whole app. If you're updating **from before 4.4**, RemSound now offers — the first time you run it — to **bring your shortcuts across** from one of your existing profiles: it lists your profiles, you pick the one you set your shortcuts up in, or choose to start fresh. (If you already updated to 4.4, nothing changes for you here.)
+
+## A clearer Keyboard shortcuts dialog
+
+- A new **Clear this shortcut** button next to Close, so clearing a shortcut is discoverable — you no longer have to know the Del key.
+- When you're setting a shortcut, pressing **Delete** in that box now leaves it unassigned.
+
+## Clearer remote-control labels
+
+The three remote-control rows that adjust a peer's **RemSound** volume now say so — "Send remote RemSound volume up / down to peers" and "Send remote RemSound receive mute toggle to peers" — so they're easy to tell apart from the "Windows global volume" rows.
 
 ## Compatibility
 
-**v4.4 talks to v3.3 through v4.3 with no trouble** — the over-the-network format is unchanged, so you don't have to update both ends at once. (Everyone still needs **v3.3 or newer**, where end-to-end encryption came in.)
+**v4.5 talks to v3.3 through v4.4 with no trouble** — the over-the-network format is unchanged, so you don't have to update both ends at once. (Everyone still needs **v3.3 or newer**, where end-to-end encryption came in.)
 
 ## Install
 
-1. Download `RemSound-v4.4.zip` from this release.
+1. Download `RemSound-v4.5.zip` from this release.
 2. Close RemSound.
 3. Extract the zip **over your existing RemSound folder**, overwriting program files when prompted. The zip is program files only — it won't touch your settings, profiles, logs or recordings.
 4. Run `RemSound.exe`.
 
 ## Upgrading
 
-**From v3.6 or newer:** Help → Check for updates installs v4.4 with the in-app updater — and if it can't finish, it puts your old version back exactly as it was.
+**From v3.6 or newer:** Help → Check for updates installs v4.5 with the in-app updater — and if it can't finish, it puts your old version back exactly as it was.
 
 **From v1.9–v3.5:** Check for updates works, but uses your current version's older updater for this one hop. If auto-update has been failing on your machine, install by hand using the steps above.