feat: frps-manager v1.0 - frp 0.70.1 multi-tenant web management system

- Multi-tenant client/proxy management with Flask+SQLite
- Frps server control (start/restart/token rotation)
- Generate frpc.ini with shared server token + admin API
- Dashboard API integration (live client/proxy status)
- RBAC: admin/tenant_admin/user roles
- Audit logging for all operations
- Systemd service files included
- Requires legacy INI format (frp 0.70 TOML auth broken)

templates/user_form.html

@@ -0,0 +1,36 @@
+{% extends "base.html" %}
+{% block title %}{{ '编辑' if item else '新建' }}用户 · frps-manager{% endblock %}
+{% block content %}
+<h1>{{ '编辑用户' if item else '新建用户' }}</h1>
+<form method="post" class="form-card">
+  {% if item %}
+  <label>用户名 <input value="{{ item.username }}" disabled></label>
+  {% else %}
+  <label>用户名 <input name="username" required pattern="[a-zA-Z0-9_.-]+"></label>
+  {% endif %}
+  <label>显示名 <input name="display_name" value="{{ item.display_name or '' if item else '' }}"></label>
+  <label>密码 {% if item %}<span class="muted small">(留空表示不修改)</span>{% endif %}
+    <input name="password" type="password" {% if not item %}required{% endif %} minlength="6">
+  </label>
+  <label>角色
+    <select name="role">
+      <option value="user" {% if item and item.role == 'user' %}selected{% endif %}>user (普通用户，只能看自己的租户)</option>
+      <option value="tenant_admin" {% if item and item.role == 'tenant_admin' %}selected{% endif %}>tenant_admin (租户管理员)</option>
+      <option value="admin" {% if item and item.role == 'admin' %}selected{% endif %}>admin (系统管理员)</option>
+    </select>
+  </label>
+  <label>归属租户
+    <select name="tenant_id">
+      <option value="">(不绑定)</option>
+      {% for t in tenants %}
+      <option value="{{ t.id }}" {% if item and item.tenant_id == t.id %}selected{% endif %}>{{ t.name }}</option>
+      {% endfor %}
+    </select>
+  </label>
+  <label class="checkbox"><input type="checkbox" name="is_active" {% if item is none or item.is_active %}checked{% endif %}> 启用</label>
+  <div class="form-actions">
+    <button class="btn btn-primary" type="submit">保存</button>
+    <a class="btn" href="{{ url_for('users_list') }}">取消</a>
+  </div>
+</form>
+{% endblock %}