鉴权并入 Auth Broker：委派设备会话统一模型 + 四端迁移

后端（委托 Auth Broker，路径 A）：
- 删自建鉴权（OIDC exchange / 自签会话 / step-up / shortcut / web_sessions / accounts），cdrop 不再存任何凭证；鉴权中间件改读边缘注入的 X-Auth-Subject/Scope/Meta/Name/Roles 头（dev 旁路保留）；Claims 加 Tier() / Guest()
- internal/brokerclient：mint / revoke（带 X-Broker-App）/ refresh / ListSessions（R1 列举），直连内网、吊销幂等

统一会话模型“委派设备会话”（Delegated Device Sessions）：
- 每个客户端（浏览器 / 桌面 / 扫码设备）＝一条带 meta(device_id) + label 的 broker 机器会话；Broker 作设备会话唯一注册表（R1 按用户＋app 列举 + R2 按 (user,app,meta) 幂等铸造），cdrop 退化为薄覆盖层、不再自存权威会话表
- 新增代铸端点 POST /api/auth/device-session：凭边缘已验明的 X-Auth-Subject 委托 broker 铸 / 轮换设备会话（meta=device_id、按调用方 tier 防越权、sameOrigin CSRF、per-IP 限流）；R2 幂等保证同一 device_id 重登原地轮换、不堆重复设备
- 会话列表＝R1 权威 + 叠加 type（本地缓存）/ online（Hub presence，按设备名）/ current（meta 匹配本请求 X-Auth-Meta）+ 过滤 meta=""（device-authorize 引导会话残留）；devices 表降级为 type/presence 薄缓存（非会话权威），device_id 主键、upsert 按 user 限定
- 吊销按 device_id → 缓存优先 / R1 兜底解析 sid → broker 吊销 + X-Broker-App；扫码登录保留三密钥编排，collect 改委托 broker 铸 + 落缓存行

Web 前端：
- 登录走 broker 全局 SSO 代跳（/api/auth/login 302）；bootstrap 经 /api/me 注入身份后代铸设备会话（稳定 device_id 存 localStorage、Web Locks 跨 tab 串行防重复铸造）；refresh 走 /api/auth/refresh
- 设备管理按 device_id；改名＝同 device_id 重代铸（R2 原地轮换换 label、不产生重复行）；登录页反应式守卫修登录回环
- 去 OIDC PKCE / step-up（删 oauth.callback / stepUp）

桌面客户端（Wails）：
- loopback PKCE（RFC 8252）改指 broker 设备授权流（/device/authorize + /device/token）拿引导令牌，再代铸出带 meta 的托管设备会话——与浏览器同模型、同管理、同吊销；身份取自代铸响应（修“显示名显示为 UUID”）；refresh 保留显示名；稳定 device_id 入桌面配置

iOS 客户端（arch A，原生 SwiftUI + 离屏无头 WebView 引擎 + 原生↔JS 桥）：
- 引擎 / 文件管理 / 设备管理 / 应用图标 / 本地化（此前实现，随本次落入版本库）
- 鉴权＝引擎自刷（boot 注入 refresh_token）+ broker 轮换经 sessionRotated 回报原生更新 Keychain；去 cookie 同步；Session 加 refreshToken / deviceId

实时 / 健壮性：
- presence 走 Hub union（设备表行 ∪ 表外实时连接，按名去重、live-only 标在线）
- Hub 通道 close 一律在写锁内、非阻塞 send 一律在读锁内，消除 close-vs-send 闭通道 send panic（revoke 每次 Kick 后该路径变热）

配置 / 删旧栈：
- config 改 broker 接入（CDROP_BROKER_* / CDROP_PUBLIC_URL / 按档 TTL），prod 强校验 broker 配置 + PUBLIC_URL（CSRF Origin 守卫不失效）
- 删 auth.go / selftoken.go / shortcut.go / jwks.go + 三表（web_sessions / accounts / shortcut_tokens）及验证链；.env.example / compose.snippet.yaml / Caddyfile.snippet 更新为 broker 模型（人机分流 + 公开端点放行 + X-Auth-Meta 透传）
- 测试全重写：QR / 会话含 mock broker（R1 列举 + R2 幂等）；hub 加 close-vs-send 并发回归；config 加 prod 必填校验

internal/hub/hub_test.go

@@ -2,6 +2,8 @@ package hub
 
 import (
 	"context"
+	"fmt"
+	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -44,7 +46,7 @@ func TestConnectFiresPresenceEvent(t *testing.T) {
 	h := New(lister)
 	defer h.Close()
 
-	c := h.Connect(context.Background(), "alice", "tab-1")
+	c := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	defer h.Disconnect(c)
 
 	ev := waitForEvent(t, c, "presence", time.Second)
@@ -65,11 +67,11 @@ func TestSecondClientSeesFirstAsOnline(t *testing.T) {
 	h := New(lister)
 	defer h.Close()
 
-	c1 := h.Connect(context.Background(), "alice", "tab-1")
+	c1 := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	defer h.Disconnect(c1)
 	_ = waitForEvent(t, c1, "presence", time.Second)
 
-	c2 := h.Connect(context.Background(), "alice", "tab-2")
+	c2 := h.Connect(context.Background(), "alice", "tab-2", "browser")
 	defer h.Disconnect(c2)
 
 	// c2 receives its own presence (announced on Connect).
@@ -94,12 +96,28 @@ func TestSecondClientSeesFirstAsOnline(t *testing.T) {
 	}
 }
 
+// A live device with no devices-table row (global-SSO browser / broker-auth desktop)
+// must still appear in presence as online, labelled by its declared type.
+func TestLiveOnlyDeviceAppearsInPresence(t *testing.T) {
+	h := New(&fakeLister{}) // empty managed-device set
+	defer h.Close()
+
+	c := h.Connect(context.Background(), "alice", "macbook", "macos")
+	defer h.Disconnect(c)
+
+	ev := waitForEvent(t, c, "presence", time.Second)
+	devs, _ := ev.Data.(map[string]any)["devices"].([]PresenceDevice)
+	if len(devs) != 1 || devs[0].Name != "macbook" || devs[0].Type != "macos" || !devs[0].Online {
+		t.Errorf("live-only device should appear online in presence: %+v", devs)
+	}
+}
+
 func TestSendToRoutesEvent(t *testing.T) {
 	lister := &fakeLister{}
 	h := New(lister)
 	defer h.Close()
 
-	c := h.Connect(context.Background(), "alice", "tab-1")
+	c := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	defer h.Disconnect(c)
 	_ = waitForEvent(t, c, "presence", time.Second)
 
@@ -124,11 +142,11 @@ func TestReconnectClosesOldChannel(t *testing.T) {
 	h := New(&fakeLister{})
 	defer h.Close()
 
-	old := h.Connect(context.Background(), "alice", "tab-1")
+	old := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	// drain the initial presence so we can detect close
 	<-old.Events()
 
-	_ = h.Connect(context.Background(), "alice", "tab-1")
+	_ = h.Connect(context.Background(), "alice", "tab-1", "browser")
 
 	select {
 	case _, ok := <-old.Events():
@@ -146,7 +164,7 @@ func TestDisconnectRemovesFromOnlineSet(t *testing.T) {
 	})
 	defer h.Close()
 
-	c := h.Connect(context.Background(), "alice", "tab-1")
+	c := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	if !h.Online("alice", "tab-1") {
 		t.Fatal("client should be online after Connect")
 	}
@@ -156,6 +174,36 @@ func TestDisconnectRemovesFromOnlineSet(t *testing.T) {
 	}
 }
 
+// TestConcurrentKickAndPresenceNoPanic hammers Kick (which closes channels under the write
+// lock) against publishPresence / Broadcast / SendTo (non-blocking sends under the read lock).
+// Before the close-vs-send fix this raced into a "send on closed channel" panic that crashed
+// the whole process; now close and send are mutually exclusive. Run with -race.
+func TestConcurrentKickAndPresenceNoPanic(t *testing.T) {
+	h := New(&fakeLister{
+		devices: []db.Device{{UserID: "u", Name: "d", Type: "browser"}},
+	})
+	defer h.Close()
+
+	const workers = 16
+	const iters = 200
+	var wg sync.WaitGroup
+	for i := 0; i < workers; i += 1 {
+		wg.Add(1)
+		go func(n int) {
+			defer wg.Done()
+			name := fmt.Sprintf("d%d", n)
+			for j := 0; j < iters; j += 1 {
+				h.Connect(context.Background(), "u", name, "browser")
+				h.PublishPresence(context.Background(), "u")
+				h.Broadcast("u", Event{Type: "x"})
+				h.SendTo("u", name, Event{Type: "y"})
+				h.Kick("u", name)
+			}
+		}(i)
+	}
+	wg.Wait()
+}
+
 // TestGracePeriod uses a tiny grace so the test runs fast.
 func TestGracePeriodDelaysOfflinePresence(t *testing.T) {
 	h := New(&fakeLister{
@@ -167,9 +215,9 @@ func TestGracePeriodDelaysOfflinePresence(t *testing.T) {
 	h.grace = 100 * time.Millisecond
 	defer h.Close()
 
-	c1 := h.Connect(context.Background(), "alice", "tab-1")
+	c1 := h.Connect(context.Background(), "alice", "tab-1", "browser")
 	defer h.Disconnect(c1)
-	c2 := h.Connect(context.Background(), "alice", "tab-2")
+	c2 := h.Connect(context.Background(), "alice", "tab-2", "browser")
 	// Drain initial presence frames
 	_ = waitForEvent(t, c1, "presence", time.Second)
 	_ = waitForEvent(t, c1, "presence", time.Second)