chore: import SiteForge Factory V5 source (baseline)

导入 SiteForge Factory V5 基线源码：
- FastAPI + SQLite + Docker Compose（Web + Worker）架构
- 四套商业主题 × 14 页面模板（1.1.0，含历史版本快照）
- 四种建站模式骨架 + 迁移审计 + 发布门禁
- 52 项 pytest 测试
- 补全计划主文档 docs/superpowers/plans/

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

compose.public.yaml

@@ -0,0 +1,26 @@
+# 在正式 DNS / HTTPS 域名配置完成后才启用：
+# docker compose -f compose.yaml -f compose.public.yaml up -d --build
+services:
+  siteforge:
+    environment:
+      SITEFORGE_COOKIE_SECURE: "true"
+      SITEFORGE_ALLOWED_HOSTS: "${SITEFORGE_DOMAIN},localhost,127.0.0.1"
+  caddy:
+    image: caddy:2-alpine
+    restart: unless-stopped
+    depends_on:
+      siteforge:
+        condition: service_healthy
+    ports:
+      - "80:80"
+      - "443:443"
+      - "443:443/udp"
+    environment:
+      SITEFORGE_DOMAIN: ${SITEFORGE_DOMAIN:?Set SITEFORGE_DOMAIN in .env}
+    volumes:
+      - ./deploy/Caddyfile:/etc/caddy/Caddyfile:ro
+      - caddy_data:/data
+      - caddy_config:/config
+volumes:
+  caddy_data:
+  caddy_config: