feat(admin): Phase 4 质量词 Admin(平台单层) — QualityWord + 生成侧读配置(无配置回落) + 质量词页

后端:apps/ai QualityWord(stage/slot/text/sort/enabled)+ migration;services.py quality_words/quality_suffix,
4 个 builder 接入(person/model_tryon/storyboard/video)无配置回落原写死值零回归;adminpanel CRUD + 审计。
前端:adminApi quality 系列;Admin 质量词页(按 stage 分组卡 + 编辑模式开关 + 行内增改删 chip)。
测试:adminpanel 23 + accounts 22 = 45 单测过(CRUD/权限/生成读配置+回落/停用词不取);
无头 e2e _admin-p4.mjs 4 断言过 + 0 console error + live 库零残留;tsc+build 绿。
注:apps.ai 3 个 image_edit 路由测试失败为进场前既有(已 stash 比对 HEAD 同样失败),非本 Phase 引入。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/backend/apps/ai/models.py

@@ -107,3 +107,28 @@ class AITask(TeamOwnedModel):
     def __str__(self) -> str:
         return f"{self.task_type}:{self.status}:{self.id}"
 
+
+class QualityWord(TimeStampedModel):
+    """平台单层质量词配置:按生成阶段(stage)+ 槽位(slot)挂若干质量词,
+    生成侧拼提示词时优先读取本配置;**无配置则回落各 builder 的写死值**(零回归)。
+    全平台共用一套(不挂 team),团队级覆盖以后再说。"""
+
+    class Stage(models.TextChoices):
+        PERSON = "person", "人物立绘"
+        MODEL_TRYON = "model_tryon", "模特上身图"
+        STORYBOARD = "storyboard", "故事板"
+        VIDEO = "video", "视频"
+
+    stage = models.CharField(max_length=24, choices=Stage.choices)
+    slot = models.CharField(max_length=24, default="quality")
+    text = models.CharField(max_length=200)
+    sort = models.IntegerField(default=0)
+    enabled = models.BooleanField(default=True)
+
+    class Meta:
+        ordering = ["stage", "sort", "created_at"]
+        indexes = [models.Index(fields=["stage", "slot"])]
+
+    def __str__(self) -> str:
+        return f"{self.stage}/{self.slot}/{self.text}"
+