fix: move ENV PATH before npm ci to bust stale Docker cache layer

The cached npm ci layer predates the ENV PATH instruction, so tsc was
never on PATH when the build ran. Moving ENV PATH earlier changes the
cache key and forces a fresh install.

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

sync/Dockerfile

@@ -1,10 +1,10 @@
 # Stage 1: build TypeScript
 FROM node:20-alpine AS builder
 WORKDIR /app
+ENV PATH="/app/node_modules/.bin:$PATH"
 RUN apk add --no-cache python3 make g++
 COPY package*.json ./
 RUN npm ci --include=dev
-ENV PATH="/app/node_modules/.bin:$PATH"
 COPY tsconfig.json ./
 COPY src ./src
 RUN npm run build && npm prune --production