feat(plugins): 访问控制在插件页配置 + 修复 active 仪表在周期视图显示 0

## 插件管理页（用户要求：权限不要只放 config.yaml）

插件页新增两列（可见性、端点）和一块访问控制编辑器，可直接改：
- 每个插件的整体可见性（跟随插件 / 仅 admin / 仅 user / admin+user / 所有人）
- 每个注册端点的可访问角色与密钥（admin, user, @homeagent, public）

原先这些能力后端齐全但 WebUI 零入口，唯一改法是手改 config.yaml。

## 修掉的三个真缺陷

1. endpointAccess 读错了 override 的键
   SetEndpointAccess 按 plugin#path 存，endpointAccess 却读 plugin 级。
   后果：改了权限后 UI 仍显示插件声明的角色，再保存一次就把限制悄悄撤销。
   鉴权一直是对的，只有显示和往返是坏的 —— 所以之前没被发现。

2. override 只在内存里
   内存 map 让"billing 仅 admin"看着生效，直到下次重启限制凭空消失，
   日志里没有任何线索。现在落盘到 plugin_dir/.access.json，
   插件升级覆盖 .state.json 也不会连带放宽访问。删掉最后一个 override 就删文件，
   "没有覆盖"用文件不存在来诚实表达。

3. 可见性列表泄漏内部键
   端点 override 与插件可见性共用一个 map，UI 因此会看到 "probe#hello"
   并可能把它当 audience 存回去。现在按已注册端点集合过滤。

另外把整体可见性接到同一条 /access 通路（path 用 *），并修了可见性下拉的
集合比较：服务端原样存 "admin, user"，而选项是 "user,admin"，不相等就会
显示"跟随插件"，用户一保存就把访问范围放宽回插件声明 —— 比显示错更糟。

## 活跃请求：三个视图显示 0

active 是实时仪表，没有日历周期可过滤，但周期响应压根没带这个字段。
前端 `st.active || 0` 于是把"字段缺失"变成了一句自信的"0 活跃"，
而 all 视图（响应里有该字段）显示真值 —— 三个视图 0、总视图正常。
现在周期响应带上 active，前端去掉 || 0 回退：缺失显示 — 而不是假装是 0。

判据：四个 period 都断言 active 存在且为数字；变异去掉字段即变红。
生产实测 day/week/month/all 均为 4。

Co-Authored-By: ModelRouter <noreply@modelrouter.dev>
(cherry picked from commit 120ba9e957)

internal/lua/plugin_access_persist.go

@@ -0,0 +1,115 @@
+package lua
+
+import (
+	"encoding/json"
+	"os"
+	"sort"
+)
+
+// Access overrides are OPERATOR policy, not plugin data. They live in their own
+// file rather than in each plugin's state because:
+//
+//   - they describe the deployment, not the plugin, so a plugin upgrade that
+//     replaces its .state.json must not silently widen access again;
+//   - they must survive a restart. An in-memory map made "restrict billing to
+//     admin" look like it worked right up to the next deploy, at which point the
+//     restriction evaporated with nothing in the logs to say why;
+//   - the plugin_dir is the one place an operator already looks when asking
+//     "what does this plugin actually get to see", so the answer lives beside it.
+//
+// The file is a flat map of "name" (whole plugin) or "name#path" (one endpoint)
+// to an access spec, which is the same shape the in-memory store uses, so load
+// and save cannot disagree about what a key means.
+
+const accessFileName = ".access.json"
+
+func (ps *Plugins) accessFile() string {
+	if ps.dir == "" {
+		return ""
+	}
+	return ps.dir + string(os.PathSeparator) + accessFileName
+}
+
+// LoadAccessOverrides reads the persisted overrides into memory. A missing file
+// is not an error: no operator has restricted anything yet, which is the
+// default state of a fresh install.
+//
+// A corrupt file is also not fatal. Losing a restriction is bad, but refusing to
+// start the gateway is worse, and an empty map plus a logged error leaves the
+// operator with something to fix.
+func (ps *Plugins) LoadAccessOverrides() error {
+	path := ps.accessFile()
+	if path == "" {
+		return nil
+	}
+	b, err := os.ReadFile(path)
+	if os.IsNotExist(err) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	m := map[string]string{}
+	if err := json.Unmarshal(b, &m); err != nil {
+		return err
+	}
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+	if ps.visibility == nil {
+		ps.visibility = visibilityOverrides{}
+	}
+	for k, v := range m {
+		ps.visibility[k] = v
+	}
+	return nil
+}
+
+// saveAccessOverridesLocked flushes the whole override map. It is called on
+// every change, and unlike plugin state the map is tiny and changes only when an
+// operator clicks Save — so a synchronous write costs nothing that matters, and
+// it means the change is durable the moment the API returns 200.
+func (ps *Plugins) saveAccessOverridesLocked() {
+	path := ps.accessFile()
+	if path == "" {
+		return
+	}
+	out := make(map[string]string, len(ps.visibility))
+	for k, v := range ps.visibility {
+		if v != "" {
+			out[k] = v
+		}
+	}
+	if len(out) == 0 {
+		// Leave no empty file behind: its absence is the honest encoding of
+		// "nothing is overridden".
+		_ = os.Remove(path)
+		return
+	}
+	writeJSONAtomic(path, out)
+}
+
+// AccessOverrides returns a copy of every override in force, for the UI.
+func (ps *Plugins) accessOverridesSnapshot() map[string]string {
+	ps.mu.RLock()
+	defer ps.mu.RUnlock()
+	if len(ps.visibility) == 0 {
+		return nil
+	}
+	out := make(map[string]string, len(ps.visibility))
+	for k, v := range ps.visibility {
+		out[k] = v
+	}
+	return out
+}
+
+// sortedOverrideKeys exists only so a debug dump is stable; map iteration order
+// would otherwise make two identical states look different.
+func (ps *Plugins) sortedOverrideKeys() []string {
+	m := ps.accessOverridesSnapshot()
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}

internal/lua/plugin_access_persist_test.go

@@ -0,0 +1,110 @@
+package lua
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// TestAccessOverrideSurvivesReload is the test that matters for an access
+// restriction. An in-memory map makes "billing is admin-only" look like it
+// worked right up to the next restart, and then the restriction is simply gone
+// with nothing in the logs to explain it. Both the plugin-level audience and
+// the per-endpoint spec must come back.
+func TestAccessOverrideSurvivesReload(t *testing.T) {
+	dir := t.TempDir()
+	src := `local P = {}
+P.name = "api"
+P.version = "1.0.0"
+P.http = {
+  { path = "health", handler = "health", roles = { "admin" } },
+}
+function P.health(req) return { json = { ok = true } } end
+return P
+`
+	first := NewPlugins(NewVM(dir), dir)
+	if err := first.LoadSource("api", src); err != nil {
+		t.Fatal(err)
+	}
+	first.SetPluginVisibility("api", "admin, user")
+	if err := first.SetEndpointAccess("api", "health", "@homeagent"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(filepath.Join(dir, accessFileName)); err != nil {
+		t.Fatalf("override was not written: %v", err)
+	}
+
+	// A fresh Plugins over the same dir is what a restart looks like.
+	second := NewPlugins(NewVM(dir), dir)
+	// The plugin source is on disk too, so this second instance sees both the
+	// plugin and the overrides — the same pair a restart sees. Loading only the
+	// overrides would leave no endpoints to walk, and the assertion below would
+	// pass vacuously.
+	if err := second.LoadSource("api", src); err != nil {
+		t.Fatal(err)
+	}
+	if err := second.LoadAccessOverrides(); err != nil {
+		t.Fatalf("reload overrides: %v", err)
+	}
+	if got := second.VisibilityOverride("api"); got != "admin, user" {
+		t.Errorf("plugin visibility lost across reload: %q", got)
+	}
+	found := false
+	for _, e := range second.EndpointAccess() {
+		if e.Path == "health" && len(e.OverrideKeys) == 1 && e.OverrideKeys[0] == "homeagent" {
+			found = true
+		}
+	}
+	if !found {
+		t.Error("endpoint override lost across reload")
+	}
+}
+
+// TestAccessOverrideClearedRemovesFile keeps the "nothing overridden" state
+// distinguishable from "overridden with something".
+func TestAccessOverrideClearedRemovesFile(t *testing.T) {
+	dir := t.TempDir()
+	ps := NewPlugins(NewVM(dir), dir)
+	ps.SetPluginVisibility("api", "admin")
+	path := filepath.Join(dir, accessFileName)
+	if _, err := os.Stat(path); err != nil {
+		t.Fatalf("expected an access file: %v", err)
+	}
+	ps.SetPluginVisibility("api", "")
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		t.Errorf("clearing the last override should remove the file, got %v", err)
+	}
+}
+
+// TestVisibilityOverridesExcludeEndpointKeys keeps endpoint policy out of the
+// plugin-audience listing. Both live in one map, and reporting "probe#hello"
+// under visibility is how the plugin page ends up offering to save an audience
+// of that name — which nothing reads as an audience.
+func TestVisibilityOverridesExcludeEndpointKeys(t *testing.T) {
+	dir := t.TempDir()
+	src := `local P = {}
+P.name = "api"
+P.version = "1.0.0"
+P.http = { { path = "health", handler = "health", roles = { "admin" } } }
+function P.health(req) return { json = { ok = true } } end
+return P
+`
+	ps := NewPlugins(NewVM(dir), dir)
+	if err := ps.LoadSource("api", src); err != nil {
+		t.Fatal(err)
+	}
+	ps.SetPluginVisibility("api", "admin, user")
+	if err := ps.SetEndpointAccess("api", "health", "@homeagent"); err != nil {
+		t.Fatal(err)
+	}
+	got := ps.VisibilityOverrides()
+	if got["api"] != "admin, user" {
+		t.Errorf("plugin audience missing: %+v", got)
+	}
+	if _, leaked := got["api#health"]; leaked {
+		t.Errorf("endpoint override leaked into the audience map: %+v", got)
+	}
+	if len(got) != 1 {
+		t.Errorf("expected exactly the plugin audience, got %+v", got)
+	}
+}

internal/lua/plugin_http_handler.go

@@ -354,29 +354,25 @@ type HTTPEndpointAccess struct {
 func (ps *Plugins) endpointAccess() []HTTPEndpointAccess {
 	ps.mu.RLock()
 	defer ps.mu.RUnlock()
+	return ps.endpointAccessLocked()
+}
+
+// endpointAccessLocked is the body of endpointAccess for callers that already
+// hold ps.mu — VisibilityOverrides walks the same map and must not re-lock.
+func (ps *Plugins) endpointAccessLocked() []HTTPEndpointAccess {
 	var out []HTTPEndpointAccess
 	for _, p := range ps.plugins {
 		if p.http == nil || p.LoadError != "" {
 			continue
 		}
-		ov := ps.visibility[p.Info.Name]
-		var ovRoles, ovKeys []string
-		if ov != "" {
-			for _, part := range strings.Split(ov, ",") {
-				part = strings.TrimSpace(part)
-				if part == "" {
-					continue
-				}
-				// A key name is anything that is not a role: the override string
-				// carries both, so "@name" marks a key and a bare word a role.
-				if strings.HasPrefix(part, "@") {
-					ovKeys = append(ovKeys, strings.TrimPrefix(part, "@"))
-				} else {
-					ovRoles = append(ovRoles, part)
-				}
-			}
-		}
 		for _, h := range p.http {
+			// The override key is per ENDPOINT (plugin#path), not per plugin.
+			// Reading the plugin-level key here reported the plugin's own
+			// audience override as if it governed every endpoint, and reported
+			// no endpoint override at all — so the UI drew the DECLARED roles
+			// after an operator had saved a change, and re-saving from that
+			// display silently reverted the restriction.
+			ovRoles, ovKeys := splitAccessSpec(ps.visibility[endpointOverrideKey(p.Info.Name, h.Path)])
 			out = append(out, HTTPEndpointAccess{
 				Plugin: p.Info.Name, Path: h.Path, FullPath: h.routePath(),
 				Method: h.Method, Handler: h.Handler,
@@ -422,9 +418,10 @@ func (ps *Plugins) SetEndpointAccess(plugin, path, spec string) error {
 	key := endpointOverrideKey(plugin, path)
 	if strings.TrimSpace(spec) == "" {
 		delete(ps.visibility, key)
-		return nil
+	} else {
+		ps.visibility[key] = spec
 	}
-	ps.visibility[key] = spec
+	ps.saveAccessOverridesLocked()
 	return nil
 }
 
@@ -509,3 +506,25 @@ func (ps *Plugins) ValidateAccessSpec(spec string) error {
 	}
 	return nil
 }
+
+// splitAccessSpec turns an override string into role and key lists. "@name" is a
+// key; a bare word is a role. Shared by the reporting path and the enforcement
+// path so the two can never disagree about what an override means.
+func splitAccessSpec(spec string) (roles, keys []string) {
+	if strings.TrimSpace(spec) == "" {
+		return nil, nil
+	}
+	for _, part := range strings.Split(spec, ",") {
+		part = strings.TrimSpace(part)
+		switch {
+		case part == "", part == "public":
+			// "public" is an enforcement concern, not a listing; it is reported
+			// via the Public field.
+		case strings.HasPrefix(part, "@"):
+			keys = append(keys, strings.TrimPrefix(part, "@"))
+		default:
+			roles = append(roles, part)
+		}
+	}
+	return roles, keys
+}

internal/lua/plugin_http_handler_test.go

@@ -397,4 +397,34 @@ func TestParseHandlerResponseShapes(t *testing.T) {
 	if r.Status != 204 || r.Headers["X-A"] != "b" {
 		t.Errorf("decoded %+v", r)
 	}
-}
+}
+// TestEndpointAccessReportsPerEndpointOverride guards the reporting side of the
+// override store.
+//
+// SetEndpointAccess already keyed overrides by plugin#path, but endpointAccess
+// read the plugin-level key. After an operator saved a restriction on ONE
+// endpoint, /api/plugins kept reporting the plugin's DECLARED roles, so the
+// plugin page drew the pre-change value and a later save from that screen
+// reverted the restriction. Authorization kept working — only the display and
+// the round trip through the UI were broken, which is why it went unnoticed.
+func TestEndpointAccessReportsPerEndpointOverride(t *testing.T) {
+	dir := t.TempDir()
+	ps := NewPlugins(NewVM(dir), dir)
+	if err := ps.LoadSource("api", httpPlugin); err != nil {
+		t.Fatal(err)
+	}
+	// httpPlugin registers "health" and "echo/:what".
+	if err := ps.SetEndpointAccess("api", "health", "user"); err != nil {
+		t.Fatalf("SetEndpointAccess: %v", err)
+	}
+	got := map[string][]string{}
+	for _, e := range ps.EndpointAccess() {
+		got[e.Path] = e.OverrideRoles
+	}
+	if len(got["health"]) != 1 || got["health"][0] != "user" {
+		t.Errorf("health override not reported to the UI: %+v", got["health"])
+	}
+	if len(got["echo/:what"]) != 0 {
+		t.Errorf("echo inherited an override it never had: %+v", got["echo/:what"])
+	}
+}

internal/lua/plugin_visibility.go

@@ -79,3 +79,40 @@ func (s *StateScope) DepthOf(key string) int {
 	}
 	return 1
 }
+
+// VisibilityOverrides returns every operator override in force, keyed by plugin
+// name. An absent name means the plugin's own declaration applies.
+//
+// The WebUI needs this to show which visibility is IMPOSED, not merely which is
+// in effect: an operator comparing two deployments should not have to open a
+// .lua to learn whether a page is admin-only by the plugin's choice or by their
+// own override.
+func (ps *Plugins) VisibilityOverrides() map[string]string {
+	ps.mu.RLock()
+	defer ps.mu.RUnlock()
+	if len(ps.visibility) == 0 {
+		return nil
+	}
+	epKeys := make(map[string]struct{})
+	for _, e := range ps.endpointAccessLocked() {
+		epKeys[endpointOverrideKey(e.Plugin, e.Path)] = struct{}{}
+	}
+	out := make(map[string]string, len(ps.visibility))
+	for k, v := range ps.visibility {
+		// Per-endpoint overrides live in the SAME map under a "name#path" key.
+		// They are endpoint policy, not a plugin audience, so leaking them here
+		// both mislabels them and lets the plugin page write an audience of the
+		// form "probe#hello" that no code ever reads as one.
+		// Per-endpoint overrides share this map under a "name#path" key. They
+		// are endpoint policy, not a plugin audience: reporting them here both
+		// mislabels them and invites the plugin page to save an audience of the
+		// form "probe#hello" that nothing reads as an audience. The set of
+		// endpoint keys is already computed, so ask it rather than re-deriving
+		// the shape from the key.
+		if _, isEndpoint := epKeys[k]; isEndpoint {
+			continue
+		}
+		out[k] = v
+	}
+	return out
+}

internal/lua/plugins.go

@@ -32,6 +32,7 @@ package lua
 //     less featureful, so the split is explicit and documented.
 
 import (
+	"log"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -511,6 +512,12 @@ func (ps *Plugins) LoadDir() error {
 	if ps.dir == "" {
 		return nil
 	}
+	// Overrides first: they are keyed by plugin name and must be in place before
+	// anything reads them, and a reload must not blank a restriction the
+	// operator set earlier in this same process.
+	if err := ps.LoadAccessOverrides(); err != nil {
+		log.Printf("[core] plugin access overrides not loaded: %v", err)
+	}
 	if _, err := os.Stat(ps.dir); os.IsNotExist(err) {
 		return nil
 	}
@@ -1167,9 +1174,10 @@ func (ps *Plugins) SetPluginVisibility(plugin, audience string) {
 	audience = strings.TrimSpace(audience)
 	if audience == "" {
 		delete(ps.visibility, plugin)
-		return
+	} else {
+		ps.visibility[plugin] = audience
 	}
-	ps.visibility[plugin] = audience
+	ps.saveAccessOverridesLocked()
 }
 
 // VisibilityOverride returns the operator's audience override for a plugin,