fix(db): 重编号合并后撞号 migration，并修 admin e2e base

将 015–023 双文件冲突线性化为 015–050；提供已有库 schema_migrations 修复脚本；admin Playwright 对齐 /psy/admin/ 预览路径。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/migrations/000037_knowledge_chunks.up.sql

@@ -0,0 +1,19 @@
+-- ECR-027 KnowledgeChunk (read catalog)
+
+CREATE TABLE IF NOT EXISTS knowledge_chunks (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  code varchar(64) NOT NULL UNIQUE,
+  source_code varchar(64) NOT NULL,
+  title varchar(128) NOT NULL,
+  body text NOT NULL,
+  active boolean NOT NULL DEFAULT true,
+  system boolean NOT NULL DEFAULT false,
+  created_at timestamptz NOT NULL DEFAULT now(),
+  updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_knowledge_chunks_active ON knowledge_chunks(active);
+
+INSERT INTO knowledge_chunks(code, source_code, title, body, active, system)
+VALUES ('ask_grounding_intro', 'ask_grounding', '问答 grounding 引言块', '愈心谷提供陪伴式成长对话，非医疗诊断。', true, true)
+ON CONFLICT (code) DO NOTHING;