chore: post-deployment cleanup and docs update

- Make AI routing rules DB-driven (read from system_configs, removed from config.py)
- Add translation quota tracking to LLM translation (OpenAIProvider)
- Add Alibaba MT ECS RAM role support (STS token, no AccessKey needed)
- Fix admin sidebar link for AI模型配置 page
- Fix Quota.vue API path (quotas → translation-quotas)
- Fix login auto-redirect to dashboard
- Add provider dropdown selects to AI routing config UI
- Clean up stale ai_provider_* system_configs records
- Remove OpencodeGo, Spark providers (code + DB)
- Update deploy config: nginx port 8000, systemd cwd

backend/app/services/translation_quota.py

@@ -12,6 +12,10 @@ class TranslationQuotaService:
     def __init__(self, db: AsyncSession):
         self.db = db
 
+    def _default_desc(self, version: str) -> str:
+        labels = {"ecommerce": "阿里云翻译电商版", "general": "阿里云翻译通用版", "llm": "AI模型翻译"}
+        return labels.get(version, f"阿里云翻译{version}版")
+
     async def _get_or_create(self, version: str) -> TranslationQuota:
         result = await self.db.execute(
             select(TranslationQuota).where(TranslationQuota.version == version)
@@ -25,7 +29,7 @@ class TranslationQuotaService:
                 used_chars=0,
                 current_month=now.strftime("%Y-%m"),
                 enabled=True,
-                description=f"阿里云翻译{version}版",
+                description=self._default_desc(version),
             )
             self.db.add(quota)
             await self.db.flush()
@@ -57,8 +61,7 @@ class TranslationQuotaService:
         return remaining
 
     async def get_all_quotas(self) -> list:
-        default_versions = ["ecommerce", "general"]
-        for v in default_versions:
+        for v in ("ecommerce", "general", "llm"):
             await self._get_or_create(v)
 
         result = await self.db.execute(select(TranslationQuota).order_by(TranslationQuota.version))