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/change_password.html

@@ -0,0 +1,13 @@
+{% extends "base.html" %}
+{% block title %}修改密码 · frps-manager{% endblock %}
+{% block content %}
+<h1>修改密码</h1>
+<form method="post" class="form-card">
+  <label>当前密码 <input name="old_password" type="password" required></label>
+  <label>新密码 (至少 6 位) <input name="new_password" type="password" required minlength="6"></label>
+  <div class="form-actions">
+    <button class="btn btn-primary" type="submit">保存</button>
+    <a class="btn" href="{{ url_for('dashboard') }}">取消</a>
+  </div>
+</form>
+{% endblock %}