Merge branch 'cd/aur-implementation': AUR rewrite with go-git, RPC batch queries, functional options

# Conflicts:
#	flatpak/capabilities.go
#	ports/capabilities.go
#	ports/capabilities_openbsd.go
#	ports/ports_test.go
#	snap/capabilities.go
#	snap/snap_linux.go
#	snap/snap_other.go

flatpak/capabilities_linux.go

@@ -0,0 +1,56 @@
+//go:build linux
+
+package flatpak
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/gogrlx/snack"
+)
+
+func latestVersion(ctx context.Context, pkg string) (string, error) {
+	out, err := run(ctx, []string{"remote-info", "flathub", pkg})
+	if err != nil {
+		if strings.Contains(err.Error(), "exit status 1") {
+			return "", fmt.Errorf("flatpak latestVersion %s: %w", pkg, snack.ErrNotFound)
+		}
+		return "", fmt.Errorf("flatpak latestVersion: %w", err)
+	}
+	// remote-info output is key:value like `flatpak info`
+	p := parseInfo(out)
+	if p == nil || p.Version == "" {
+		return "", fmt.Errorf("flatpak latestVersion %s: %w", pkg, snack.ErrNotFound)
+	}
+	return p.Version, nil
+}
+
+func listUpgrades(ctx context.Context) ([]snack.Package, error) {
+	out, err := run(ctx, []string{"remote-ls", "--updates", "--columns=name,application,version,origin"})
+	if err != nil {
+		// No updates available may produce an error on some versions
+		if strings.Contains(err.Error(), "No updates") {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("flatpak listUpgrades: %w", err)
+	}
+	return parseList(out), nil
+}
+
+func upgradeAvailable(ctx context.Context, pkg string) (bool, error) {
+	upgrades, err := listUpgrades(ctx)
+	if err != nil {
+		return false, err
+	}
+	for _, u := range upgrades {
+		if u.Name == pkg || u.Description == pkg {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+func versionCmp(_ context.Context, ver1, ver2 string) (int, error) {
+	return semverCmp(ver1, ver2), nil
+}

flatpak/capabilities_other.go

@@ -0,0 +1,25 @@
+//go:build !linux
+
+package flatpak
+
+import (
+	"context"
+
+	"github.com/gogrlx/snack"
+)
+
+func latestVersion(_ context.Context, _ string) (string, error) {
+	return "", snack.ErrUnsupportedPlatform
+}
+
+func listUpgrades(_ context.Context) ([]snack.Package, error) {
+	return nil, snack.ErrUnsupportedPlatform
+}
+
+func upgradeAvailable(_ context.Context, _ string) (bool, error) {
+	return false, snack.ErrUnsupportedPlatform
+}
+
+func versionCmp(_ context.Context, _, _ string) (int, error) {
+	return 0, snack.ErrUnsupportedPlatform
+}