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/cmd/backfill-exif/main.go

@@ -7,11 +7,11 @@ import (
 	"os"
 	"strings"
 
-	"shared-album/internal/config"
-	"shared-album/internal/db"
-	"shared-album/internal/settings"
-	"shared-album/internal/storage"
-	"shared-album/internal/store"
+	"galo/internal/config"
+	"galo/internal/db"
+	"galo/internal/settings"
+	"galo/internal/storage"
+	"galo/internal/store"
 )
 
 func main() {

backend/cmd/migrate/main.go

@@ -5,9 +5,9 @@ import (
 	"log/slog"
 	"os"
 
-	assets "shared-album"
-	"shared-album/internal/config"
-	"shared-album/internal/db"
+	assets "galo"
+	"galo/internal/config"
+	"galo/internal/db"
 )
 
 func main() {

backend/cmd/reconcile/main.go

@@ -14,13 +14,13 @@ import (
 	"strings"
 	"time"
 
-	assets "shared-album"
-	"shared-album/internal/config"
-	"shared-album/internal/db"
-	"shared-album/internal/reconcile"
-	"shared-album/internal/settings"
-	"shared-album/internal/storage"
-	"shared-album/internal/store"
+	assets "galo"
+	"galo/internal/config"
+	"galo/internal/db"
+	"galo/internal/reconcile"
+	"galo/internal/settings"
+	"galo/internal/storage"
+	"galo/internal/store"
 )
 
 const objectPrefix = "objects/"

backend/cmd/server/main.go

@@ -13,23 +13,27 @@ import (
 	"syscall"
 	"time"
 
-	assets "shared-album"
-	"shared-album/internal/app"
-	"shared-album/internal/auth"
-	"shared-album/internal/config"
-	"shared-album/internal/db"
-	"shared-album/internal/settings"
-	"shared-album/internal/sse"
-	"shared-album/internal/storage"
-	"shared-album/internal/store"
+	assets "galo"
+	"galo/internal/app"
+	"galo/internal/auth"
+	"galo/internal/config"
+	"galo/internal/db"
+	"galo/internal/settings"
+	"galo/internal/sse"
+	"galo/internal/storage"
+	"galo/internal/store"
 )
 
+// version is set at build time via -ldflags "-X main.version=..."
+var version = "dev"
+
 func main() {
 	loadDotEnv(".env")
 	loadDotEnv("../.env")
 
 	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
 	slog.SetDefault(logger)
+	slog.Info("starting galo", "version", version)
 
 	cfg, err := config.Load()
 	if err != nil {