feat(api): 统一公开接口为 /api/v1 前缀

将通用生成、Gemini、可灵、火山、健康检查与 OpenAPI 的推荐入口统一到 /api/v1，并保留历史路径作为兼容别名。同步更新代理配置、接入文档、接口清单和前缀回归测试。\n\n验证：go vet ./...；go test ./...；pnpm openapi；pnpm lint；pnpm test；pnpm build；公开 OpenAPI 71 个方法与接口清单机器比对一致。

docker-compose.yml

@@ -87,7 +87,7 @@ services:
       postgres:
         condition: service_healthy
     healthcheck:
-      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1:8088/readyz | grep -q '\"ok\":true'"]
+      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1:8088/api/v1/readyz | grep -q '\"ok\":true'"]
       interval: 10s
       timeout: 5s
       retries: 20
@@ -117,7 +117,7 @@ services:
       api:
         condition: service_healthy
     healthcheck:
-      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1/gateway-api/healthz | grep -q 'easyai-ai-gateway'"]
+      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1/api/v1/healthz | grep -q 'easyai-ai-gateway'"]
       interval: 10s
       timeout: 5s
       retries: 20