fix: revert npm ci back to npm install in docker builds

package-lock.json was generated on Windows and only locks
@esbuild/win32-x64, no linux-x64 entry. npm ci installs strictly
from lockfile and fails with "package @esbuild/linux-x64 could not
be found" on Linux build hosts. npm install resolves the correct
platform binary even when absent from the lock.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docker/Dockerfile

@@ -1,7 +1,7 @@
 FROM node:20-alpine AS node-builder
 WORKDIR /app
-COPY package.json package-lock.json ./
-RUN npm ci --ignore-scripts
+COPY package.json ./
+RUN npm install --ignore-scripts
 COPY . .
 RUN npm run build:icons && npm run build
 

docker/nginx.Dockerfile

@@ -1,7 +1,7 @@
 FROM node:20-alpine AS node-builder
 WORKDIR /app
-COPY package.json package-lock.json ./
-RUN npm ci --ignore-scripts
+COPY package.json ./
+RUN npm install --ignore-scripts
 COPY . .
 RUN npm run build:icons && npm run build