Massive rework of platform layer user/organization

The goal of this rework is to make it so I can pass around platform.User
instead of a pair of models.Organization and models.User. This is useful
for reason I kind of forget now, but it started with working on
notifications and ballooned massively from there into refactoring a
number of things that were bugging me.

This also includes a tiny amount of work on server-side events (SSE).

 * background stuff lives inside the platform now, which I need for
   having it push updates through SSE
 * userfile now lives in the platform, under file, so other platform
   functions can safely use it
 * oauth is broken into pieces and inside platform because other stuff
   was calling it already, but badly.
 * notifications go into the platform as well

platform/subprocess/audio.go

@@ -0,0 +1,60 @@
+package subprocess
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+
+	"github.com/Gleipnir-Technology/nidus-sync/platform/file"
+	"github.com/google/uuid"
+	"github.com/rs/zerolog/log"
+)
+
+func fileContentPathAudioNormalized(u uuid.UUID) string {
+	//destination := AudioFileContentPathNormalized(audioUUID.String())
+	return file.ContentPath(file.CollectionAudioNormalized, u)
+}
+func NormalizeAudio(audioUUID uuid.UUID) error {
+	//source := AudioFileContentPathRaw(audioUUID.String())
+	source := file.ContentPath(file.CollectionAudioRaw, audioUUID)
+	_, err := os.Stat(source)
+	if errors.Is(err, os.ErrNotExist) {
+		log.Warn().Str("source", source).Msg("file doesn't exist, skipping normalization")
+		return nil
+	}
+	log.Info().Str("source", source).Msg("Normalizing")
+	//destination := AudioFileContentPathNormalized(audioUUID.String())
+	destination := fileContentPathAudioNormalized(audioUUID)
+	// Use "ffmpeg" directly, assuming it's in the system PATH
+	cmd := exec.Command("ffmpeg", "-i", source, "-filter:a", "loudnorm", destination)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Printf("FFmpeg output for normalization: %s", out)
+		return fmt.Errorf("ffmpeg normalization failed: %v", err)
+	}
+	log.Info().Str("destination", destination).Msg("Normalized audio")
+	return nil
+}
+
+func TranscodeToOgg(audioUUID uuid.UUID) error {
+	//source := AudioFileContentPathNormalized(audioUUID.String())
+	source := fileContentPathAudioNormalized(audioUUID)
+	_, err := os.Stat(source)
+	if errors.Is(err, os.ErrNotExist) {
+		log.Warn().Str("source", source).Msg("file doesn't exist, skipping OGG transcoding")
+		return nil
+	}
+	log.Info().Str("source", source).Msg("Transcoding to ogg")
+	//destination := userfile.AudioFileContentPathOgg(audioUUID.String())
+	destination := file.ContentPath(file.CollectionAudioTranscoded, audioUUID)
+	// Use "ffmpeg" directly, assuming it's in the system PATH
+	cmd := exec.Command("ffmpeg", "-i", source, "-vn", "-acodec", "libvorbis", destination)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Error().Err(err).Bytes("out", out).Msg("FFmpeg output for OGG transcoding")
+		return fmt.Errorf("ffmpeg OGG transcoding failed: %v", err)
+	}
+	log.Info().Str("destination", destination).Msg("Transcoded audio")
+	return nil
+}