ci(docker): pin pnpm 8.15.9 + fallback non-frozen (pnpm v9 approve-builds blocks install)

Dockerfile

@@ -5,10 +5,10 @@
 
 FROM node:22-alpine AS build
 RUN apk add --no-cache libc6-compat python3 make g++ git
-RUN corepack enable
+RUN corepack enable && corepack prepare [email protected] --activate
 WORKDIR /app
 COPY . .
-RUN pnpm install --frozen-lockfile || pnpm install
+RUN pnpm install --frozen-lockfile 2>/dev/null || pnpm install --no-frozen-lockfile
 RUN pnpm -C app/bridge build
 
 FROM ghcr.io/hanzoai/spa