chore: seal Design Vision v1 and monorepo scaffold

Archive the differentiated YuXinGu product docs, AI engineering system,
design contract, and Go/Vue scaffold. Next execution prioritizes Cece-parity
over early innovation (see .ai/product/STRATEGY.md).

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

.ai/deployment.md

@@ -0,0 +1,33 @@
+# Deployment — Golden Rules
+
+## Containers
+
+- Every runnable service that ships to prod must have a Dockerfile.
+- Never use image tag `latest` in production.
+- Always semantic version tags: `v0.1.0` or git SHA.
+
+## Health
+
+- Liveness: `GET /api/v1/healthz` required.
+- When DB is required for traffic: add readiness endpoint (e.g. `/api/v1/readyz`) that checks DB.
+- Alias names `/health` `/readiness` `/liveness` may map to the above; keep one canonical path documented in OpenAPI.
+
+## Config
+
+- Secrets via env only. Commit `.env.example`, never `.env`.
+- Required: `APP_ENV`, `HTTP_ADDR`, `DATABASE_URL`.
+
+## CI
+
+- No manual prod deploy as the happy path — CI builds and tags.
+- Minimum gates: `go test ./...` (api), `npm run build:h5`.
+
+## Local
+
+```bash
+docker compose -f deploy/docker-compose.yml up -d
+cd apps/api && go run ./cmd/server
+npm run dev:h5
+```
+
+If Go module download times out in CN: `export GOPROXY=https://goproxy.cn,direct`.