fix(ci): fix convex missing from prune output and npm version mismatch

Two root causes for the Docker build failures:

1. convex/_generated/api not found (both apps)
   turbo prune only traces npm workspace packages; the root convex/ directory
   is not a workspace package so it is excluded from out/full/. Copy it
   manually into the prune output after turbo prune runs.

2. @heroui/react not found (storefront)
   package-lock.json was generated with npm@11 but node:20-alpine ships
   npm@10. turbo warns it cannot parse the npm 11 lockfile and generates an
   incomplete out/package-lock.json, causing npm ci inside Docker to miss
   packages. Upgrade npm to 11 in the deps stage of both Dockerfiles.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/storefront/Dockerfile

@@ -12,6 +12,12 @@ FROM node:20-alpine AS deps
 RUN apk add --no-cache libc6-compat
 WORKDIR /app
 
+# Upgrade npm to match the project's packageManager (npm@11). The package-lock.json
+# was generated with npm 11 — npm 10 (bundled with node:20) can't fully parse it,
+# causing turbo prune to generate an incomplete pruned lockfile and npm ci to miss
+# packages like @heroui/react.
+RUN npm install -g npm@11 --quiet
+
 COPY json/ .
 COPY package-lock.json .
 RUN npm ci