feat(infra): MCP 인프라 서버 통합 — 7개 도구 + core/ 분리

mcp-infra-server를 gpu-services/infra/로 통합.
core/ 순수 로직은 Agent/NanoClaude에서도 직접 import 가능.
도구: docker_status, docker_logs, service_health, disk_usage,
tailscale_status, ollama_models, mlx_models.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

infra/config.py

@@ -0,0 +1,73 @@
+"""Host configuration and tool-host validation.
+
+All host IPs are Tailscale IPs (except nas-company which also works via Tailscale).
+"""
+
+from __future__ import annotations
+
+import os
+from dataclasses import dataclass, field
+from dotenv import load_dotenv
+
+load_dotenv()
+
+
+@dataclass(frozen=True)
+class HostConfig:
+    ip: str
+    user: str
+    auth: str                          # "key" | "password"
+    docker_path: str = "docker"
+    needs_sudo: bool = False
+    password: str | None = None        # only for auth="password"
+
+
+HOSTS: dict[str, HostConfig] = {
+    "gpu": HostConfig(
+        ip="100.111.160.84",
+        user="hyungi",
+        auth="key",
+    ),
+    "macmini": HostConfig(
+        ip="100.76.254.116",
+        user="hyungi",
+        auth="key",
+    ),
+    "nas-company": HostConfig(
+        ip="100.71.132.52",
+        user="hyungi",
+        auth="password",
+        docker_path="/usr/local/bin/docker",
+        needs_sudo=True,
+        password=os.getenv("NAS_COMPANY_PASSWORD"),
+    ),
+}
+
+# Per-tool allowed hosts — invalid host → immediate error
+TOOL_HOST_MAP: dict[str, list[str]] = {
+    "docker_status":  ["gpu", "nas-company"],
+    "docker_logs":    ["gpu", "nas-company"],
+    "disk_usage":     ["gpu", "macmini", "nas-company"],
+    "ollama_models":  ["gpu", "macmini"],
+    "mlx_models":     ["macmini"],
+}
+
+# SSH timeouts
+SSH_TIMEOUT = 5       # connection timeout (seconds)
+CMD_TIMEOUT = 10      # command execution timeout (seconds)
+MAX_RETRIES = 1       # retry once on failure
+
+
+def validate_host(tool: str, host: str) -> HostConfig:
+    """Validate host is allowed for tool and return config. Raises ValueError if invalid."""
+    allowed = TOOL_HOST_MAP.get(tool)
+    if allowed and host not in allowed:
+        raise ValueError(
+            f"'{host}'는 {tool}에서 지원하지 않습니다. 허용: {', '.join(allowed)}"
+        )
+    config = HOSTS.get(host)
+    if not config:
+        raise ValueError(
+            f"알 수 없는 호스트: '{host}'. 허용: {', '.join(HOSTS.keys())}"
+        )
+    return config