fix(orchestrator): add prisma CLI as devDependency for prisma:generate script

The prisma:generate script added in #703 calls 'prisma generate' but the
prisma CLI was not installed in the orchestrator package. Adding it as a
devDependency so pnpm can resolve it during the monorepo build step.

apps/orchestrator/Dockerfile

@@ -21,8 +21,7 @@ FROM base AS deps
 COPY packages/shared/package.json ./packages/shared/
 COPY packages/config/package.json ./packages/config/
 COPY apps/orchestrator/package.json ./apps/orchestrator/
-# Copy API package.json + prisma schema so prisma generate can find the project root
-COPY apps/api/package.json ./apps/api/package.json
+# Copy API prisma schema so prisma generate can run in the orchestrator build
 COPY apps/api/prisma ./apps/api/prisma
 
 # Copy npm configuration for native binary architecture hints
@@ -49,8 +48,7 @@ COPY --from=deps /app/packages/shared/node_modules ./packages/shared/node_module
 COPY --from=deps /app/packages/config/node_modules ./packages/config/node_modules
 COPY --from=deps /app/apps/orchestrator/node_modules ./apps/orchestrator/node_modules
 
-# Copy API package.json + prisma schema so Prisma can find the project root
-COPY apps/api/package.json ./apps/api/package.json
+# Copy API prisma schema and generate the Prisma client for the orchestrator
 COPY apps/api/prisma ./apps/api/prisma
 RUN pnpm --filter=@mosaic/orchestrator prisma:generate