feat: rename service to galo, add halo branding and release build

- rename Go module, binary, systemd unit, PG_DATABASE default, frontend package and docs from shared-album to galo
- add theme-aware halo emblem and favicon (new ui-branding capability)
- add make build-release (versioned, stripped, static binary) and run the binary from the repo root

backend/internal/storage/s3_test.go

@@ -13,7 +13,7 @@ import (
 	"testing"
 	"time"
 
-	"shared-album/internal/config"
+	"galo/internal/config"
 )
 
 func newTestS3(t *testing.T) (*S3, *Signer) {

backend/internal/storage/storage.go

@@ -17,7 +17,7 @@ import (
 	"github.com/aws/aws-sdk-go-v2/service/s3/types"
 	"github.com/aws/smithy-go"
 
-	"shared-album/internal/config"
+	"galo/internal/config"
 )
 
 // ErrSignedURLInvalid is returned when an app-served object URL has a missing,