feat(03-01): add shared postgres pool and plugin migrations

Open one pgx stdlib *sql.DB, hand it to GORM, and run per-plugin
gormigrate sets with isolated history tables after an ICU pl-PL check.

Co-authored-by: Cursor <cursoragent@cursor.com>

bonfire/command_test.go

@@ -0,0 +1,14 @@
+package bonfire
+
+import (
+	"io"
+	"testing"
+)
+
+func TestValidBareRuntimeCommandNames(t *testing.T) {
+	for _, name := range []string{"serve", "migrate", "migrate:rollback", "migrate:status", "build", "dev"} {
+		if _, err := NewRoot("app", []Command{{Name: name}}, io.Discard); err != nil {
+			t.Fatalf("%s: %v", name, err)
+		}
+	}
+}