ci(docker): collapse build to a single npm ci to fix slow builds

The previous server/Dockerfile had parallel build + deps stages each
running npm ci against ~500 Cosmos packages — they contended for
registry bandwidth and the build was sitting at "deps 4/4" for 15+
minutes on cold cache.

- Single build stage: npm ci once, run tsc, then npm prune --omit=dev
  to drop devDependencies before copying to runtime.
- --ignore-scripts: blue-js-sdk and @coinbase/x402 postinstalls are
  inert (one is a console notice, the other has || true fallback);
  esbuild/fsevents only matter on dev. Skipping is safe and avoids
  any future hangs.
- --no-audit --no-fund: less log noise, less work.
- Add server/.dockerignore to keep build context lean.
- Switch GHA cache export to mode=min: only the final layer is
  persisted, which is plenty for a single-stage install.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 2 people

.github/workflows/build.yml

@@ -42,4 +42,4 @@ jobs:
             ghcr.io/${{ env.REPO }}:latest
             ghcr.io/${{ env.REPO }}:${{ github.sha }}
           cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-to: type=gha,mode=min

server/.dockerignore

@@ -0,0 +1,10 @@
+node_modules
+dist
+.env
+.env.*
+*.log
+test
+README.md
+.dockerignore
+Dockerfile
+docker-compose.yml

server/Dockerfile

@@ -4,16 +4,11 @@
 FROM node:22-alpine AS build
 WORKDIR /app
 COPY package.json package-lock.json* ./
-RUN npm ci
+RUN npm ci --ignore-scripts --no-audit --no-fund --loglevel=error
 COPY tsconfig.json ./
 COPY src ./src
-RUN npm run build
-
-# ─── Production deps only ───
-FROM node:22-alpine AS deps
-WORKDIR /app
-COPY package.json package-lock.json* ./
-RUN npm ci --omit=dev
+RUN npm run build \
+ && npm prune --omit=dev --ignore-scripts
 
 # ─── Runtime ───
 FROM node:22-alpine AS runtime
@@ -24,7 +19,7 @@ ENV FACILITATOR_PORT=4021
 
 RUN addgroup -S app && adduser -S app -G app
 
-COPY --from=deps  /app/node_modules ./node_modules
+COPY --from=build /app/node_modules ./node_modules
 COPY --from=build /app/dist         ./dist
 COPY package.json ./