Patch logger for ISO8601 TZ offsets and fix Docker build

- server/logger.ts: timestamps now use local TZ offset instead of Z
- Dockerfile: replaced 'npm ci --omit=dev' with 'npm install --omit=dev' to fix Alpine build failure
- References discussion: https://github.com/orgs/fosrl/discussions/1025
- Note: timestamps default to +00:00 (UTC) unless the user sets environment: TZ=<timezone> in docker-compose.yaml

Optional future improvement: include tzdata in the container for shell/date consistency.

Dockerfile

@@ -29,7 +29,9 @@ RUN apk add --no-cache curl
 
 # COPY package.json package-lock.json ./
 COPY package*.json ./
-#RUN npm ci --omit=dev && npm cache clean --force
+
+# 'npm ci --omit=dev' with 'npm install --omit=dev' to fix Alpine build failure
+# RUN npm ci --omit=dev && npm cache clean --force
 RUN npm install --omit=dev && npm cache clean --force
 
 COPY --from=builder /app/.next/standalone ./

server/logger.ts

@@ -6,6 +6,7 @@ import { APP_PATH } from "./lib/consts";
 import telemetryClient from "./lib/telemetry";
 
 // helper to get ISO8601 string in the TZ from process.env.TZ
+// This replaces the default Z (UTC) with the local offset from process.env.TZ
 const isoLocal = () => {
     const tz = process.env.TZ || "UTC";
     const d = new Date();
@@ -15,6 +16,8 @@ const isoLocal = () => {
     const pad = (n: number) => String(n).padStart(2, "0");
     const hours = pad(Math.floor(Math.abs(tzOffsetMin) / 60));
     const mins = pad(Math.abs(tzOffsetMin) % 60);
+
+    // Replace Z in ISO string with local offset
     return s.replace(" ", "T") + `${sign}${hours}:${mins}`;
 };
 
@@ -74,6 +77,8 @@ const logger = winston.createLogger({
         winston.format.errors({ stack: true }),
         winston.format.colorize(),
         winston.format.splat(),
+
+        // Use isoLocal so timestamps respect TZ env, not just UTC
         winston.format.timestamp({ format: isoLocal }),
         hformat
     ),