feat(cli): add interactive config input and Makefile

- support interactive value input for `config set`
- hide API key input and output
- add Makefile for build, test, vet, coverage, and cleanup
- add golang.org/x/term dependency
- update changelog and gitignore

cmd/ry/internal/config/interactive.go

@@ -0,0 +1,43 @@
+package config
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+
+	"golang.org/x/term"
+)
+
+// ReadSecret prompts the user with msg and reads a line from stdin.
+// When stdin is a terminal, echo is disabled so the typed value stays
+// invisible. When stdin is piped (non-TTY) it falls back to a normal
+// read so scripting still works.
+func ReadSecret(msg string) (string, error) {
+	fmt.Fprint(os.Stderr, msg)
+	var value string
+	if term.IsTerminal(int(os.Stdin.Fd())) {
+		b, err := term.ReadPassword(int(os.Stdin.Fd()))
+		if err != nil {
+			return "", err
+		}
+		value = string(b)
+	} else {
+		sc := bufio.NewScanner(os.Stdin)
+		if !sc.Scan() {
+			return "", sc.Err()
+		}
+		value = sc.Text()
+	}
+	fmt.Fprintln(os.Stderr)
+	return value, nil
+}
+
+// ReadLine prompts the user with msg and reads a normal (echo-enabled) line.
+func ReadLine(msg string) (string, error) {
+	fmt.Fprint(os.Stderr, msg)
+	sc := bufio.NewScanner(os.Stdin)
+	if !sc.Scan() {
+		return "", sc.Err()
+	}
+	return sc.Text(), nil
+}