first round of files

internal/domain/git/agit.go

@@ -0,0 +1,22 @@
+package git
+
+import "strings"
+
+// ParseAGitRef extracts target and source branch from an AGit push ref.
+// AGit refs follow the pattern: refs/for/<target>[/<source>]
+// Returns ("", "", false) if the ref is not an AGit ref.
+func ParseAGitRef(ref string) (target, source string, ok bool) {
+	const prefix = "refs/for/"
+	if !strings.HasPrefix(ref, prefix) {
+		return "", "", false
+	}
+	rest := strings.TrimPrefix(ref, prefix)
+	parts := strings.SplitN(rest, "/", 2)
+	target = parts[0]
+	if len(parts) == 2 {
+		source = parts[1]
+	} else {
+		source = target
+	}
+	return target, source, true
+}