refactor: 代理节点架构重构与功能增强

aether-proxy:
- 重构 main.rs，拆分为 app/state/hardware/net 模块
- setup.rs 拆分为 setup/tui.rs + setup/service.rs，支持 systemd 服务管理子命令
- 新增 delegate 端点，支持后端通过代理节点转发请求而非传统 CONNECT 代理
- 注册时上报硬件信息（CPU/内存/fd_limit）和估算最大并发数
- 心跳上报活跃连接数，支持远程下发 node_name 配置
- HTTP 转发时剥离 X-Forwarded-* 等敏感头部
- 切换到 rustls-tls，降低日志级别减少噪音

后端:
- 从 http_client.py 提取代理相关逻辑至 proxy_node/resolver.py
- 从 routes.py 提取业务逻辑至 proxy_node/service.py
- handler 支持 delegate 模式（通过代理节点 HTTP 端点转发而非 CONNECT 隧道）
- ProxyNode 模型新增 hardware_info 和 estimated_max_concurrency 字段

前端:
- 新增 HardwareTooltip 组件展示节点硬件信息
- 远程配置支持下发 node_name

alembic/versions/20260208_1200_5c6d7e8f9a0b_add_hardware_info_to_proxy_nodes.py

@@ -0,0 +1,60 @@
+"""Add hardware_info and estimated_max_concurrency to proxy_nodes
+
+Revision ID: 5c6d7e8f9a0b
+Revises: 4b5c6d7e8f9a
+Create Date: 2026-02-08 12:00:00.000000
+
+"""
+
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from sqlalchemy import inspect
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "5c6d7e8f9a0b"
+down_revision: str | None = "4b5c6d7e8f9a"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def column_exists(table_name: str, column_name: str) -> bool:
+    bind = op.get_bind()
+    inspector = inspect(bind)
+    columns = [c["name"] for c in inspector.get_columns(table_name)]
+    return column_name in columns
+
+
+def upgrade() -> None:
+    if not column_exists("proxy_nodes", "hardware_info"):
+        op.add_column(
+            "proxy_nodes",
+            sa.Column(
+                "hardware_info",
+                sa.JSON(),
+                nullable=True,
+                comment="硬件信息 (cpu_cores, total_memory_mb, os_info, fd_limit, ...)",
+            ),
+        )
+
+    if not column_exists("proxy_nodes", "estimated_max_concurrency"):
+        op.add_column(
+            "proxy_nodes",
+            sa.Column(
+                "estimated_max_concurrency",
+                sa.Integer(),
+                nullable=True,
+                comment="基于硬件估算的最大并发连接数",
+            ),
+        )
+
+
+def downgrade() -> None:
+    if column_exists("proxy_nodes", "estimated_max_concurrency"):
+        op.drop_column("proxy_nodes", "estimated_max_concurrency")
+    if column_exists("proxy_nodes", "hardware_info"):
+        op.drop_column("proxy_nodes", "hardware_info")