feat(qoder): refresh model catalog, add capability mapping and image pass-through

- Registry/constants: drop qmodel_preview/gm51model, add lite,
  qmodel_38max (Qwen3.8-Max), qfmodel (Qwen3.8-Flash), gmodel (GLM-5.3),
  gfmodel (GLM-5.3-Flash)
- capabilities: add PROVIDER_CAPABILITIES['qoder'] so opaque internal
  ids resolve to their real models' context windows and limits
- executor: preserve image blocks instead of flattening away, convert
  Claude-style image blocks, and hash images into chat_record_id
- tests: cover image preservation, data-URI and Claude-block conversion
- build(docker): use CN mirrors for apk and npm

Dockerfile

@@ -2,14 +2,15 @@
 ARG NODE_IMAGE=node:22-alpine
 FROM ${NODE_IMAGE} AS base
 WORKDIR /app
+# CN mirror for apk (used by builder and runner stages)
+RUN sed -i 's|dl-cdn.alpinelinux.org|mirrors.aliyun.com|g' /etc/apk/repositories
 
 FROM base AS builder
 
 RUN apk --no-cache upgrade && apk --no-cache add python3 make g++ linux-headers
 
 COPY package.json ./
-RUN --mount=type=cache,target=/root/.npm \
-  npm install
+RUN npm install --registry=https://registry.npmmirror.com
 
 COPY . ./
 ENV NEXT_TELEMETRY_DISABLED=1