docker: install global typescript in builder and build server with tsc

Dockerfile

@@ -1,7 +1,7 @@
 FROM node:22-alpine AS builder
 
 # Install pnpm and build deps for native modules (e.g., bcrypt)
-RUN npm install -g pnpm \
+RUN npm install -g pnpm typescript \
   && apk add --no-cache python3 make g++ libc6-compat
 
 ENV npm_config_build_from_source=1 \
@@ -21,7 +21,7 @@ COPY tsconfig.server.json ./tsconfig.server.json
 COPY tsconfig.server.build.json ./tsconfig.server.build.json
 
 # Build server only (no client build)
-RUN pnpm tsc -p tsconfig.server.build.json
+RUN tsc -p tsconfig.server.build.json
 
 FROM node:22-alpine AS production