bluez: fix a2dp (cherry-pick patch)

modules/desktop-common.nix

@@ -66,7 +66,26 @@
   };
 
   # cachyos kernel overlay
-  nixpkgs.overlays = [ inputs.nix-cachyos-kernel.overlays.default ];
+  nixpkgs.overlays = [
+    inputs.nix-cachyos-kernel.overlays.default
+    # bluez 5.86 reversed the profile-connect order (regression of cdcd845f87ee).
+    # Dual-role devices that advertise both AudioSource (UUID 0x110a) and
+    # AudioSink (UUID 0x110b) -- e.g. any A2DP headphone with an HFP mic, like
+    # the Bose QC 45 -- now negotiate audio-gateway first and never expose
+    # a2dp-sink, with bluetoothd reporting:
+    #   src/service.c:btd_service_connect() a2dp-sink profile connect failed
+    #   for <addr>: Device or resource busy
+    # Cherry-picks bluez/bluez@066a164 "a2dp: connect source profile after
+    # sink" (slated for 5.87). FIX: drop overlay when nixpkgs ships >= 5.87.
+    # see https://github.com/bluez/bluez/issues/1922
+    (_final: prev: {
+      bluez = prev.bluez.overrideAttrs (old: {
+        patches = (old.patches or [ ]) ++ [
+          ../patches/bluez/0001-a2dp-connect-source-after-sink.patch
+        ];
+      });
+    })
+  ];
 
   # kernel options
   boot = {