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/store/store_test.go

@@ -9,8 +9,8 @@ import (
 
 	"github.com/jackc/pgx/v5/pgxpool"
 
-	assets "shared-album"
-	"shared-album/internal/db"
+	assets "galo"
+	"galo/internal/db"
 )
 
 func assertComplete(t *testing.T, r Repos) {