feat: prepare Orion transcription pilot

modules/capabilities/transcription.nix

@@ -11,6 +11,7 @@ in
       ...
     }:
     let
+      isOrion = config.facts.machine.name == "orion";
       modelName = "large-v3-turbo-q5_0";
       modelHash = "sha256-OUIhcJzVrR9AxG5gMcphvOiJMebgiMGIKUxtWlX/p+I=";
       modelSha256 = builtins.convertHash {
@@ -37,6 +38,8 @@ in
           ${builtins.readFile ./_diarize-transcript.py}
         '';
       };
+      whisper = if isOrion then pkgs.whisper-cpp else pkgs.whisper-cpp-vulkan;
+      acceleration = if isOrion then "CPU" else "Vulkan";
       prepareDiarizationModel = pkgs.writeShellApplication {
         name = "prepare-transcription-diarization-model";
         runtimeInputs = with pkgs; [
@@ -72,18 +75,28 @@ in
           diarizeTranscript
           ffmpeg
           findutils
-          whisper-cpp-vulkan
+          whisper
         ];
         text = builtins.readFile ./_transcribe-recordings.sh;
       };
+      home = config.home.homeDirectory;
     in
     {
-      home.packages = with pkgs; [
-        ffmpeg
+      home.packages = [
+        pkgs.ffmpeg
         prepareDiarizationModel
-        whisper-cpp-vulkan
+        whisper
       ];
 
+      home.activation.createTranscriptionLayout = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
+        ${pkgs.coreutils}/bin/mkdir -p \
+          "${home}/sync/notes/transcripts" \
+          "${home}/sync/recordings/inbox" \
+          "${home}/sync/recordings/processing" \
+          "${home}/sync/recordings/archive" \
+          "${home}/sync/recordings/failed"
+      '';
+
       systemd.user.services.transcribe-recordings = {
         Unit.Description = "Transcribe synchronized recordings with whisper.cpp";
 
@@ -91,7 +104,8 @@ in
           Type = "oneshot";
           ExecStart = lib.getExe transcribeRecordings;
           Environment = [
-            "TRANSCRIBE_ENGINE_VERSION=${pkgs.whisper-cpp-vulkan.version}"
+            "TRANSCRIBE_ENGINE_ACCELERATION=${acceleration}"
+            "TRANSCRIBE_ENGINE_VERSION=${whisper.version}"
             "TRANSCRIBE_MODEL=${model}"
             ''"TRANSCRIBE_MODEL_NAME=${modelName} multilingual"''
             "TRANSCRIBE_MODEL_SHA256=${modelSha256}"
@@ -99,12 +113,30 @@ in
             "TRANSCRIBE_DIARIZATION_MODEL=${diarizationModel}"
             "TRANSCRIBE_DIARIZATION_MODEL_NAME=${diarizationModelName}"
             "TRANSCRIBE_DIARIZATION_MODEL_REVISION=${diarizationModelRevision}"
-            "TRANSCRIBE_SYNC_ROOT=${config.home.homeDirectory}/sync"
+            "TRANSCRIBE_SETTLE_SECONDS=300"
+            "TRANSCRIBE_SYNC_ROOT=${home}/sync"
           ];
+        }
+        // lib.optionalAttrs isOrion {
+          Restart = "on-failure";
+          RestartSec = 60;
         };
+
+        Install.WantedBy = lib.optionals isOrion [ "default.target" ];
       };
 
-      systemd.user.timers.transcribe-recordings = {
+      systemd.user.paths.transcribe-recordings = lib.mkIf isOrion {
+        Unit.Description = "Watch for synchronized recordings";
+
+        Path = {
+          PathChanged = "${home}/sync/recordings/inbox";
+          Unit = "transcribe-recordings.service";
+        };
+
+        Install.WantedBy = [ "paths.target" ];
+      };
+
+      systemd.user.timers.transcribe-recordings = lib.mkIf (!isOrion) {
         Unit.Description = "Transcribe new recordings every two minutes";
 
         Timer = {