Add /shouldibeworking endpoint, container timezone, and PowerShell CLI tracker

Ports work-time rules to the server for external polling, sets the
container TZ so schedule math matches Europe/Stockholm, and adds a
terminal-based progress tracker mirroring the web app.

server.js

@@ -39,5 +39,116 @@ app.get('/api/bridge-days', async (req, res) => {
   }
 });
 
+// ─────────────────────────────────────────────────────────────────────────────
+// /shouldibeworking — same work-time rules as public/app.js (see isWorkDay /
+// isCurrentlyWorkTime there), ported so it can be evaluated server-side.
+// ─────────────────────────────────────────────────────────────────────────────
+
+const WORK_START = 8 * 60;   // 08:00
+const LUNCH_START = 12 * 60; // 12:00
+const LUNCH_END = 13 * 60;   // 13:00
+const WORK_END = 17 * 60;    // 17:00
+
+function formatDate(date) {
+  const y = date.getFullYear();
+  const m = String(date.getMonth() + 1).padStart(2, '0');
+  const d = String(date.getDate()).padStart(2, '0');
+  return `${y}-${m}-${d}`;
+}
+
+function isWeekend(date) {
+  const d = date.getDay();
+  return d === 0 || d === 6;
+}
+
+// Matches app.js: all of July counts as non-work (Swedish summer holidays).
+function isJuly(date) {
+  return date.getMonth() === 6;
+}
+
+async function isWorkDay(date, includeBridgeDays) {
+  if (isWeekend(date)) return false;
+  if (isJuly(date)) return false;
+  const year = date.getFullYear();
+  const ds = formatDate(date);
+  const holidays = await cachedFetch(`https://api.dagsmart.se/holidays?year=${year}&weekends=false`);
+  if (holidays.some(h => h.date === ds)) return false;
+  if (includeBridgeDays) {
+    const bridgeDays = await cachedFetch(`https://api.dagsmart.se/bridge-days?year=${year}`);
+    if (bridgeDays.some(h => h.date === ds)) return false;
+  }
+  return true;
+}
+
+async function isCurrentlyWorkTime(date, includeBridgeDays) {
+  if (!(await isWorkDay(date, includeBridgeDays))) return false;
+  const mins = date.getHours() * 60 + date.getMinutes();
+  if (mins < WORK_START || mins >= WORK_END) return false;
+  if (mins >= LUNCH_START && mins < LUNCH_END) return false;
+  return true;
+}
+
+// Minutes from `now` until the working/not-working state next flips —
+// the next of WORK_START/LUNCH_START/LUNCH_END/WORK_END today, or WORK_START
+// on the next work day if none of those are left today. Rounded up, so it
+// never reads 0 while a change is still seconds away.
+async function minutesUntilNextShift(now, includeBridgeDays) {
+  const nowMins = now.getHours() * 60 + now.getMinutes() + now.getSeconds() / 60;
+
+  if (await isWorkDay(now, includeBridgeDays)) {
+    for (const boundary of [WORK_START, LUNCH_START, LUNCH_END, WORK_END]) {
+      if (boundary > nowMins) return Math.ceil(boundary - nowMins);
+    }
+  }
+
+  const cursor = new Date(now);
+  cursor.setHours(0, 0, 0, 0);
+  cursor.setDate(cursor.getDate() + 1);
+  for (let i = 0; i < 60; i++) {
+    if (await isWorkDay(cursor, includeBridgeDays)) {
+      const target = new Date(cursor);
+      target.setMinutes(WORK_START);
+      return Math.ceil((target - now) / 60000);
+    }
+    cursor.setDate(cursor.getDate() + 1);
+  }
+  return null; // no work day found within 60 days — shouldn't happen
+}
+
+// Fixed-window rate limiter: N requests per IP per window, no dependencies.
+function rateLimit({ windowMs, max }) {
+  const hits = new Map(); // ip -> { count, resetAt }
+  return (req, res, next) => {
+    const now = Date.now();
+    const entry = hits.get(req.ip);
+    if (!entry || now > entry.resetAt) {
+      hits.set(req.ip, { count: 1, resetAt: now + windowMs });
+      return next();
+    }
+    if (entry.count >= max) {
+      res.set('Retry-After', String(Math.ceil((entry.resetAt - now) / 1000)));
+      return res.status(429).json({ error: 'rate limited' });
+    }
+    entry.count++;
+    next();
+  };
+}
+
+app.get(
+  '/shouldibeworking',
+  rateLimit({ windowMs: 60 * 1000, max: 20 }),
+  async (req, res) => {
+    try {
+      const includeBridgeDays = req.query.bridgeDays === 'true';
+      const now = new Date();
+      const working = await isCurrentlyWorkTime(now, includeBridgeDays);
+      const minutesUntilChange = await minutesUntilNextShift(now, includeBridgeDays);
+      res.json({ working, includeBridgeDays, minutesUntilChange });
+    } catch (err) {
+      res.status(500).json({ error: String(err) });
+    }
+  }
+);
+
 const PORT = process.env.PORT || 3000;
 app.listen(PORT, () => console.log(`Aftersummer → http://localhost:${PORT}`));