feat: add venue booth templates for outdoor fairs

sql/cms_venue_booth_template.sql

@@ -0,0 +1,27 @@
+-- 场地展位图模板：只保存固定布局，不保存企业、预定状态或预定记录。
+-- 瀚高数据库 / PostgreSQL 兼容；可重复执行。
+
+CREATE SEQUENCE IF NOT EXISTS "cms_venue_booth_id_seq" START WITH 1 INCREMENT BY 1 NO MINVALUE NO MAXVALUE CACHE 1;
+
+CREATE TABLE IF NOT EXISTS "cms_venue_booth" (
+    "id" BIGINT NOT NULL DEFAULT nextval('"cms_venue_booth_id_seq"') PRIMARY KEY,
+    "venue_id" BIGINT NOT NULL,
+    "booth_number" VARCHAR(50) NOT NULL,
+    "position_x" INTEGER NOT NULL DEFAULT 0,
+    "position_y" INTEGER NOT NULL DEFAULT 0,
+    "create_by" VARCHAR(64) DEFAULT '',
+    "create_time" TIMESTAMP(0),
+    "update_by" VARCHAR(64) DEFAULT '',
+    "update_time" TIMESTAMP(0),
+    "remark" VARCHAR(500),
+    "del_flag" CHAR(1) DEFAULT '0'
+);
+
+COMMENT ON TABLE "cms_venue_booth" IS '场地展位图模板';
+COMMENT ON COLUMN "cms_venue_booth"."venue_id" IS '场地ID';
+COMMENT ON COLUMN "cms_venue_booth"."booth_number" IS '展位号';
+COMMENT ON COLUMN "cms_venue_booth"."position_x" IS 'X坐标';
+COMMENT ON COLUMN "cms_venue_booth"."position_y" IS 'Y坐标';
+
+CREATE UNIQUE INDEX IF NOT EXISTS "uk_cms_venue_booth_number" ON "cms_venue_booth" ("venue_id", "booth_number");
+CREATE INDEX IF NOT EXISTS "idx_cms_venue_booth_venue" ON "cms_venue_booth" ("venue_id");