GRM-12: feat: add translated operation report for success and failure cases

- Create StepTracker context manager in new report.py module
- Track each step of lifecycle operations (install, update, start, stop, enable,
  disable, status, remove) with begin/done markers
- On success: report lists all completed steps with ✓ icons
- On failure: report shows failed step (✗), completed steps before failure (✓),
  and pending steps that never started (○)
- Add translations for report header, status labels, and registry step names
  in all 5 supported languages (EN/BG/DE/RU/ZH)
- 105 tests, 100% coverage, pyright clean, ruff clean

src/gitea_runner_manager/i18n.py

@@ -425,6 +425,48 @@ TRANSLATIONS: dict[str, dict[str, str]] = {
         "ru": "неизвестно",
         "zh": "未知",
     },
+    "=== Operation Report ===": {
+        "en": "=== Operation Report ===",
+        "bg": "=== Отчет за операцията ===",
+        "de": "=== Operationsbericht ===",
+        "ru": "=== Отчет об операции ===",
+        "zh": "=== 操作报告 ===",
+    },
+    "completed": {
+        "en": "completed",
+        "bg": "завършено",
+        "de": "abgeschlossen",
+        "ru": "завершено",
+        "zh": "已完成",
+    },
+    "pending": {
+        "en": "pending",
+        "bg": "чакащо",
+        "de": "ausstehend",
+        "ru": "в ожидании",
+        "zh": "待处理",
+    },
+    "in_progress": {
+        "en": "in progress",
+        "bg": "в процес",
+        "de": "in Bearbeitung",
+        "ru": "в процессе",
+        "zh": "进行中",
+    },
+    "Save runner '{name}' to local registry": {
+        "en": "Save runner '{name}' to local registry",
+        "bg": "Запазване на runner '{name}' в локалния регистър",
+        "de": "Runner '{name}' in lokaler Registrierung speichern",
+        "ru": "Сохранить runner '{name}' в локальном реестре",
+        "zh": "将 runner '{name}' 保存到本地注册表",
+    },
+    "Remove runner '{name}' from local registry": {
+        "en": "Remove runner '{name}' from local registry",
+        "bg": "Премахване на runner '{name}' от локалния регистър",
+        "de": "Runner '{name}' aus lokaler Registrierung entfernen",
+        "ru": "Удалить runner '{name}' из локального реестра",
+        "zh": "从本地注册表移除 runner '{name}'",
+    },
 }