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.yaml

@@ -0,0 +1,62 @@
+name: siteforge-v5
+services:
+  siteforge:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: siteforge/web:5.0
+    init: true
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:${SITEFORGE_PORT:-8787}:8787"
+    environment:
+      SITEFORGE_DATA_DIR: /data
+      SITEFORGE_ADMIN_PASSWORD: ${SITEFORGE_ADMIN_PASSWORD:?Set SITEFORGE_ADMIN_PASSWORD in .env}
+      SITEFORGE_SESSION_SECRET: ${SITEFORGE_SESSION_SECRET:?Set SITEFORGE_SESSION_SECRET in .env}
+      SITEFORGE_COOKIE_SECURE: "${SITEFORGE_COOKIE_SECURE:-false}"
+      SITEFORGE_ALLOWED_HOSTS: "${SITEFORGE_ALLOWED_HOSTS:-localhost,127.0.0.1,testserver}"
+      SITEFORGE_PUBLISH_ROOT: /published
+      SITEFORGE_REQUIRE_RELEASE_APPROVAL: "true"
+    volumes:
+      - siteforge_data:/data
+      - siteforge_published:/published
+    read_only: true
+    tmpfs:
+      - /tmp:size=128m,mode=1777
+    security_opt:
+      - no-new-privileges:true
+    cap_drop:
+      - ALL
+    pids_limit: 128
+    healthcheck:
+      test: ["CMD", "python", "-c", "import urllib.request; urllib.request.urlopen('http://127.0.0.1:8787/api/health', timeout=3)"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 30s
+  worker:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: siteforge/web:5.0
+    init: true
+    restart: unless-stopped
+    command: ["python", "-m", "app.worker"]
+    environment:
+      SITEFORGE_DATA_DIR: /data
+      SITEFORGE_JOB_POLL_SECONDS: "1.5"
+      SITEFORGE_JOB_MAX_ATTEMPTS: "3"
+    volumes:
+      - siteforge_data:/data
+    read_only: true
+    tmpfs:
+      - /tmp:size=128m,mode=1777
+    security_opt:
+      - no-new-privileges:true
+    cap_drop:
+      - ALL
+    pids_limit: 128
+
+volumes:
+  siteforge_data:
+  siteforge_published: