fix: 修复暗色主题UI对比度、端口占用死循环及多项Web表单bug

后端修复:
- engine/instances.py: Socks5Server.start() 端口占用时死循环, 增加超时和异常透传
- engine/instances.py: import time 移至顶层
- engine/instances.py: sync_instances/start_instance 容忍单实例启动失败
- run.py: 启动时 sync_instances 失败不退出进程
- web/routes.py: instances start/restart/edit 路由捕获 OSError, flash 友好提示
- api/v1.py: instances start/restart/update API 返回 JSON 错误而非 500 崩溃
- web/routes.py: toggle_user/ban_user 支持 hidden 字段语义, 缺字段时切换状态
- web/routes.py: inject_nav 增加独立 nav.dashboard 和 page_name, 修复双 active bug
- auth.py: login 路由添加 logging import, 修 NameError

前端重构:
- templates/base.html: 全局对比度提升(--text #f1f5f9, --accent #a5b4fc), 标题色显式声明, alert/modal/progress/table 完整暗色样式
- templates/base.html: main-content padding-top 修复 navbar 遮挡内容
- templates/base.html: 侧边栏 active 高亮 (白字 + elevated bg + 左边框)
- templates/base.html: 顶栏动态显示当前页面名
- templates/*.html: 统一 page-header 类, 所有图标按钮添加 title tooltip
- templates/users.html: toggle/ban 表单添加 hidden enabled/ban 字段
- templates/connections.html: fmtBytes 改为 Jinja macro, 时间格式化
- templates/dashboard.html: 时间格式化为 YYYY-MM-DD HH:MM:SS, chart canvas 高度调整
- templates/logs.html: 时间格式化为可读格式
- templates/stats.html: 提升 chart 颜色对比度
- templates/system.html: 使用 time.localtime() 显示本地时间

web/routes.py

@@ -12,15 +12,33 @@ bp = Blueprint("web", __name__)
 @bp.app_context_processor
 def inject_nav():
     from flask import session as flask_session
+    p = request.path
+    if p == "/" or p.startswith("/dashboard"):
+        page_name = "仪表盘"
+    elif p.startswith("/instances"):
+        page_name = "代理实例"
+    elif p.startswith("/users"):
+        page_name = "用户管理"
+    elif p == "/stats":
+        page_name = "流量统计"
+    elif p.startswith("/stats/connections"):
+        page_name = "活跃连接"
+    elif p.startswith("/logs"):
+        page_name = "审计日志"
+    elif p.startswith("/system"):
+        page_name = "系统管理"
+    else:
+        page_name = ""
     return {
         "nav": {
-            "instances": request.path.startswith("/instances") or
-                         request.path == "/" or request.path == "/dashboard",
-            "users": request.path.startswith("/users"),
-            "stats": request.path.startswith("/stats"),
-            "logs": request.path.startswith("/logs"),
-            "system": request.path.startswith("/system"),
+            "dashboard": p == "/" or p.startswith("/dashboard"),
+            "instances": p.startswith("/instances"),
+            "users": p.startswith("/users"),
+            "stats": p.startswith("/stats"),
+            "logs": p.startswith("/logs"),
+            "system": p.startswith("/system"),
         },
+        "page_name": page_name,
         "logged_in": flask_session.get("logged_in", False),
     }
 
@@ -45,8 +63,11 @@ def instances():
 @bp.route("/instances/<int:iid>/start", methods=["POST"])
 @login_required
 def start_instance(iid):
-    current_app.instance_manager.start_instance(iid)
-    flash("实例已启动", "success")
+    try:
+        current_app.instance_manager.start_instance(iid)
+        flash("实例已启动", "success")
+    except OSError as e:
+        flash(f"启动失败（端口可能被占用）: {e}", "danger")
     return redirect(url_for("web.instances"))
 
 
@@ -61,8 +82,11 @@ def stop_instance(iid):
 @bp.route("/instances/<int:iid>/restart", methods=["POST"])
 @login_required
 def restart_instance(iid):
-    current_app.instance_manager.restart_instance(iid)
-    flash("实例已重启", "info")
+    try:
+        current_app.instance_manager.restart_instance(iid)
+        flash("实例已重启", "info")
+    except OSError as e:
+        flash(f"重启失败（端口可能被占用）: {e}", "danger")
     return redirect(url_for("web.instances"))
 
 
@@ -116,7 +140,10 @@ def edit_instance(iid):
     db.session.commit()
 
     if inst.running:
-        current_app.instance_manager.restart_instance(iid)
+        try:
+            current_app.instance_manager.restart_instance(iid)
+        except OSError as e:
+            flash(f"重启失败（端口可能被占用）: {e}", "warning")
 
     flash("配置已更新", "success")
     return redirect(url_for("web.instances"))
@@ -205,7 +232,19 @@ def delete_user(uid):
 @bp.route("/users/<int:uid>/toggle", methods=["POST"])
 @login_required
 def toggle_user(uid):
-    enabled = "enabled" in request.form
+    # 支持两种调用方式:
+    # 1) 隐藏字段 enabled=on/off (web form)
+    # 2) 不带字段时切换当前状态 (传统行为, 防止表单无字段导致总是禁用)
+    if "enabled" in request.form:
+        enabled = request.form.get("enabled") in ("on", "true", "1", "yes")
+    else:
+        from models import User
+        from database import db
+        u = db.session.query(User).get(uid)
+        if not u:
+            flash("用户不存在", "danger")
+            return redirect(url_for("web.users"))
+        enabled = not u.enabled
     result = current_app.user_service.toggle_user(uid, enabled)
     flash("已" + ("启用" if enabled else "禁用") + "该用户", "success")
     return redirect(url_for("web.users"))
@@ -214,7 +253,17 @@ def toggle_user(uid):
 @bp.route("/users/<int:uid>/ban", methods=["POST"])
 @login_required
 def ban_user(uid):
-    banned = "ban" in request.form
+    # 同 toggle_user 的两种调用方式
+    if "ban" in request.form:
+        banned = request.form.get("ban") in ("on", "true", "1", "yes")
+    else:
+        from models import User
+        from database import db
+        u = db.session.query(User).get(uid)
+        if not u:
+            flash("用户不存在", "danger")
+            return redirect(url_for("web.users"))
+        banned = not u.banned
     result = current_app.user_service.ban_user(uid, banned)
     flash("已" + ("封禁" if banned else "解封") + "该用户", "success")
     return redirect(url_for("web.users"))
@@ -265,7 +314,7 @@ def system():
                            sys_version=platform.python_version(),
                            sys_platform=platform.platform(),
                            sys_hostname=platform.node(),
-                           uptime=time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime()))
+                           uptime=time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()))
 
 
 @bp.route("/system/backup", methods=["POST"])