internal/gitea：API 用戶端、認證與輸出基礎（#5）

- internal/gitea：僅標準庫的 HTTP 用戶端；ListAll 以 limit=50 逐頁抓滿
- 認證選序 --token → TEAI_TOKEN → tea 組態（--config/TEA_CONFIG/預設路徑）；
  token 不入輸出、日誌與錯誤訊息
- 共用輸出 --output json|table（預設 json）、--timeout（預設 30s）
- CLI 結束碼 0/2/3：用法錯誤 → 2、API 錯誤（*gitea.ErrAPI）→ 3
- 單元測試：認證選序、tea 組態解析、分頁、逾時／401／5xx 錯誤映射、輸出

實作 issue #5

internal/gitea/output_test.go

@@ -0,0 +1,88 @@
+// output_test.go 驗證共用輸出：JSON 物件順序、空清單、table 對齊與
+// 格式解析。
+package gitea
+
+import (
+	"bytes"
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+var demoFields = []Field{
+	{Name: "type"},
+	{Name: "number"},
+}
+
+func TestPrintListJSON(t *testing.T) {
+	var b bytes.Buffer
+	p := Printer{Format: FormatJSON, Out: &b}
+	err := p.PrintList(demoFields, []Values{{"issue", 5}, {"pull", 7}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got []map[string]any
+	if err := json.Unmarshal(b.Bytes(), &got); err != nil {
+		t.Fatalf("invalid JSON %q: %v", b.String(), err)
+	}
+	if len(got) != 2 || got[0]["type"] != "issue" || got[1]["number"] != float64(7) {
+		t.Fatalf("unexpected payload: %v", got)
+	}
+}
+
+func TestPrintListEmptyJSONArray(t *testing.T) {
+	var b bytes.Buffer
+	p := Printer{Format: FormatJSON, Out: &b}
+	if err := p.PrintList(demoFields, nil); err != nil {
+		t.Fatal(err)
+	}
+	if strings.TrimSpace(b.String()) != "[]" {
+		t.Fatalf("want [], got %q", b.String())
+	}
+}
+
+func TestPrintNull(t *testing.T) {
+	var b bytes.Buffer
+	p := Printer{Format: FormatJSON, Out: &b}
+	if err := p.PrintNull(); err != nil {
+		t.Fatal(err)
+	}
+	if strings.TrimSpace(b.String()) != "null" {
+		t.Fatalf("want null, got %q", b.String())
+	}
+}
+
+func TestPrintTable(t *testing.T) {
+	var b bytes.Buffer
+	p := Printer{Format: FormatTable, Out: &b}
+	if err := p.PrintList(demoFields, []Values{{"issue", 5}}); err != nil {
+		t.Fatal(err)
+	}
+	out := b.String()
+	for _, want := range []string{"type", "number", "issue", "5"} {
+		if !strings.Contains(out, want) {
+			t.Fatalf("table missing %q:\n%s", want, out)
+		}
+	}
+	if !strings.Contains(out, "─") {
+		t.Fatalf("table should have separator:\n%s", out)
+	}
+}
+
+func TestParseFormat(t *testing.T) {
+	for in, want := range map[string]Format{
+		"":        FormatJSON,
+		"json":    FormatJSON,
+		"JSON":    FormatJSON,
+		"table":   FormatTable,
+		" Table ": FormatTable,
+	} {
+		got, err := ParseFormat(in)
+		if err != nil || got != want {
+			t.Errorf("ParseFormat(%q) = %v, %v; want %v", in, got, err, want)
+		}
+	}
+	if _, err := ParseFormat("yaml"); err == nil {
+		t.Error("yaml should be rejected")
+	}
+}