feat: parse all Go CLIs with flaggy; dump bash complete.

stdlib flag dropped --hop after the query. One wrapper in internal/cli,
source <(./bin/cli/complete.go bash). Gitea #34.

internal/gitlog/args.go

@@ -0,0 +1,51 @@
+package gitlog
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/eSlider/2dph/internal/cli"
+	"github.com/integrii/flaggy"
+)
+
+type CLI struct {
+	Repo, Root, Since string
+	Limit             int
+	JSONOut           bool
+}
+
+func Parser() *flaggy.Parser {
+	c := CLI{}
+	return Bind(&c)
+}
+
+func Bind(c *CLI) *flaggy.Parser {
+	p := cli.New("git-import")
+	p.Description = "go-git history → commit leafs"
+	p.Bool(&c.JSONOut, "", "json", "JSON output")
+	p.Int(&c.Limit, "", "limit", "max commits (0 = all)")
+	p.String(&c.Since, "", "since", "RFC3339 or YYYY-MM-DD")
+	p.String(&c.Root, "", "root", "scan dir for git repos")
+	p.AddPositionalValue(&c.Repo, "repo", 1, false, "git repo path")
+	return p
+}
+
+func ParseArgs(args []string) (CLI, error) {
+	var c CLI
+	if err := cli.Parse(Bind(&c), args); err != nil {
+		return c, err
+	}
+	return c, nil
+}
+
+func ParseSince(s string) (time.Time, error) {
+	if s == "" {
+		return time.Time{}, nil
+	}
+	for _, layout := range []string{time.RFC3339, "2006-01-02"} {
+		if t, err := time.Parse(layout, s); err == nil {
+			return t, nil
+		}
+	}
+	return time.Time{}, fmt.Errorf("cannot parse --since %q", s)
+}