Initial commit: img-infinite-canvas AI design workbench MVP

Moteva-style AI design workbench replica. Home prompt creates a project;
the project page provides an infinite canvas with node drag, zoom/pan,
a design chat panel, history replay, image asset upload, and project
save/regenerate.

- Backend: go-zero, DDD layering, sqlc/pgx, optional PostgreSQL; memory
  or Redis cache; asynq job queue; MinIO/S3/R2/OSS object storage;
  sky-valley/pi agent runtime adapter.
- Frontend: Next.js App Router + Vite artifact build, TypeScript, i18n,
  shadcn/ui components, auth (OTP/Turnstile/Google/WeChat).
- Deploy: Docker Compose and k3s manifests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

deploy/config/api.docker.yaml

@@ -0,0 +1,96 @@
+Name: img_infinite_canvas-api
+Host: 0.0.0.0
+Port: 8888
+Timeout: 1200000
+MaxBytes: 33554432
+Storage:
+  Driver: postgres
+  DataSource: postgres://canvas:canvas@postgres:5432/canvas?sslmode=disable
+Cache:
+  Driver: redis
+  Addr: redis:6379
+  Password: ""
+  DB: 0
+  TTLSeconds: 300
+JobQueue:
+  Driver: asynq
+  Addr: redis:6379
+  Password: ""
+  DB: 0
+  Queue: default
+  Concurrency: 10
+  MaxRetry: 3
+  TimeoutSeconds: 900
+  ShutdownTimeoutSeconds: 30
+Realtime:
+  Driver: redis
+  Addr: redis:6379
+  Password: ""
+  DB: 0
+  ChannelPrefix: canvas:realtime
+  FallbackPollMillis: 10000
+Outbox:
+  Driver: postgres
+  DataSource: postgres://canvas:canvas@postgres:5432/canvas?sslmode=disable
+  PollMillis: 1000
+  BatchSize: 100
+Auth:
+  Region: global
+  RegionMode: manual
+  TokenSecret: local-dev-change-me
+  TokenTTLSeconds: 604800
+  RefreshTTLSeconds: 2592000
+  CodeTTLSeconds: 600
+  DevReturnCode: true
+  Email:
+    Driver: none # none|smtp
+    Host: ""
+    Port: 587
+    Username: ""
+    Password: ""
+    FromName: hello
+    FromEmail: hello@auth.moteva.local
+    BrandName: Moteva
+    UseTLS: false
+    StartTLS: true
+    InsecureSkipVerify: false
+    TimeoutSeconds: 10
+  Turnstile:
+    Enabled: true
+    SiteKey: "1x00000000000000000000AA"
+    SecretKey: "1x0000000000000000000000000000000AA"
+    SecretKeyEnv: TURNSTILE_SECRET_KEY
+    SiteVerifyURL: https://challenges.cloudflare.com/turnstile/v0/siteverify
+    TimeoutSeconds: 5
+  Google:
+    ClientID: ""
+    TokenInfoURL: https://oauth2.googleapis.com/tokeninfo
+    TimeoutSeconds: 8
+  Wechat:
+    AppID: ""
+    AppSecret: ""
+    RedirectURI: ""
+    Scope: snsapi_login
+    AuthURL: https://open.weixin.qq.com/connect/qrconnect
+    TokenURL: https://api.weixin.qq.com/sns/oauth2/access_token
+    TimeoutSeconds: 8
+Agent:
+  Driver: pi
+  Text:
+    Driver: vision
+    Model: gpt-5.4-mini
+    TimeoutSeconds: 240
+  Planner:
+    Driver: vision
+    Model: gpt-5.5
+    TimeoutSeconds: 240
+ObjectStorage:
+  Driver: minio
+  Bucket: canvas-assets
+  Endpoint: minio:9000
+  Region: us-east-1
+  AccessKey: canvas
+  SecretKey: canvas-secret
+  PublicBase: http://localhost:19000/canvas-assets
+  UseSSL: false
+  ExpiresIn: 900