feat(gateway): admin 列表端点接真实数据——persona/session/memory 补 List() 并注入 gateway.Deps

根因：gateway.Server 定义 SessionStore/PersonaStore/MemoryStore 接口但生产从未满足：
- 底层 manager 无 List() 方法；
- wireFrontend 的 gateway.Deps{} 未传 Session/Personas/Memories。
→ /api/v1/sessions|personas 与 /api/v1/admin/{sessions,personas,memories} 恒返回 []。

改动：
- persona/registry：Registry.List() []Character（并发安全、值拷贝）。
- channel/session：SessionManager.List(ctx)（查 channel_sessions 表+按 actor_role 重建）。
- runtime/memory：Store.List(ctx)（全表，复用 scanItems）。
- gateway 三 Store 接口改为返回域类型（Character/MemoryItem），映射统一放 collect* 侧。
- cmd/cyrene/wire.go：Deps 补传 Session/Personas/Memories。
- .gitignore：cyrene→/cyrene（锚定根，不再误伤 cmd/cyrene 目录）。

实机验证：/api/v1/admin/personas 返回 {id:cyrene,name:昔涟,isDefault:true}。

internal/persona/registry/registry.go

@@ -7,6 +7,7 @@ package registry
 
 import (
 	"fmt"
+	"sort"
 	"sync"
 
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/persona/emotion"
@@ -184,3 +185,20 @@ func (r *Registry) CountCharacters() int {
 	defer r.mu.RUnlock()
 	return len(r.characters)
 }
+
+// List returns every registered character, sorted by ID. Each returned Character
+// is a copy so callers cannot mutate the registry's internal state. It is safe
+// for concurrent use.
+func (r *Registry) List() []Character {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	out := make([]Character, 0, len(r.characters))
+	for _, c := range r.characters {
+		ch := *c
+		ch.Modes = append([]string(nil), c.Modes...)
+		out = append(out, ch)
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].ID < out[j].ID })
+	return out
+}

internal/persona/registry/registry_test.go

@@ -167,6 +167,53 @@ func TestRegistry_EmotionsFollowPersona(t *testing.T) {
 	}
 }
 
+func TestRegistry_List(t *testing.T) {
+	t.Parallel()
+
+	r := New()
+	// An empty registry lists nothing but stays non-nil.
+	if got := r.List(); got == nil || len(got) != 0 {
+		t.Fatalf("List() on empty registry = %#v, want empty non-nil", got)
+	}
+
+	if err := r.RegisterPersona(mkPersona("pb", "c", "")); err != nil {
+		t.Fatalf("RegisterPersona(pb): %v", err)
+	}
+	if err := r.RegisterPersona(mkPersona("pa", "c", "")); err != nil {
+		t.Fatalf("RegisterPersona(pa): %v", err)
+	}
+	if err := r.RegisterCharacter(mkChar("cb", "pb", false)); err != nil {
+		t.Fatalf("RegisterCharacter(cb): %v", err)
+	}
+	if err := r.RegisterCharacter(mkChar("ca", "pa", true)); err != nil {
+		t.Fatalf("RegisterCharacter(ca): %v", err)
+	}
+
+	got := r.List()
+	if len(got) != 2 {
+		t.Fatalf("List() = %d characters, want 2", len(got))
+	}
+	// Sorted by ID: ca before cb.
+	if got[0].ID != "ca" || got[1].ID != "cb" {
+		t.Fatalf("List() order = %q,%q, want ca,cb", got[0].ID, got[1].ID)
+	}
+	if got[0].PersonaID != "pa" || !got[0].Default || got[1].Default {
+		t.Fatalf("default/persona refs wrong: %+v", got)
+	}
+	if len(got[0].Modes) != 2 || got[0].Modes[0] != "chat" {
+		t.Fatalf("Modes = %v, want [chat home]", got[0].Modes)
+	}
+
+	// The returned slice is a copy: mutating it must not touch the registry.
+	got[0].Modes[0] = "hacked"
+	got[0].Name = "hacked"
+	// Re-read and assert the registry is unchanged.
+	ch, ok := r.Character("ca")
+	if !ok || ch.Name != "ca" || ch.Modes[0] != "chat" {
+		t.Fatalf("registry mutated through List copy: %+v", ch)
+	}
+}
+
 func TestRegistry_ConcurrentLifecycle(t *testing.T) {
 	t.Parallel()