feat: Phase 2J — staff shift scheduling

Backend:
- New model: ScheduledShift (scheduled_shifts table)
  Planning data separate from waiter_shifts (actual data) — linked conceptually by user+date
  start_time/end_time stored as "HH:MM" strings (SQLite has no native Time type)
- New router /api/schedule/:
  - GET / — list by date range + optional user_id filter
  - POST / — create scheduled shift (validates user exists)
  - PUT /{id} — update times/notes
  - DELETE /{id} — remove
  - GET /week?week_start= — full week view: scheduled shifts with actual WaiterShift
    comparison for the same user+date, estimated weekly labor cost, waiters list with rates
- Each ScheduledShiftOut includes duration_hours (handles overnight) + estimated_pay
  (duration × hourly_rate, null if rate not set)
- Migration: CREATE TABLE IF NOT EXISTS scheduled_shifts

Frontend:
- SchedulePage (/schedule): weekly calendar grid — rows = staff, columns = Mon–Sun
  - Week navigation (← Προηγ. / Αυτή η εβδομάδα / Επόμ. →)
  - Estimated weekly labor cost in header when shifts have rates
  - ShiftSlot cells: blue = scheduled only, green = scheduled + actual shift happened
    Shows scheduled times + actual start/end from real WaiterShift data
  - Click empty cell → AddShiftModal (pre-selects that row's waiter, any date in week)
  - "+" row at bottom for waiters not yet scheduled this week
  - Delete button (✕) per slot with confirm
  - Legend explaining the color scheme
- Sidebar: CalendarDays icon for Πρόγραμμα (after KDS)

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

manager_dashboard/src/pages/SchedulePage.jsx

@@ -0,0 +1,375 @@
+import { useState } from 'react'
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
+import toast from 'react-hot-toast'
+import client from '../api/client'
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+const DAY_LABELS = ['Δευ', 'Τρί', 'Τετ', 'Πέμ', 'Παρ', 'Σάβ', 'Κυρ']
+
+function fmt(n) {
+  if (n == null) return '—'
+  return n.toLocaleString('el-GR', { minimumFractionDigits: 2, maximumFractionDigits: 2 }) + ' €'
+}
+
+function weekMonday(d) {
+  const day = new Date(d)
+  const dow = day.getDay()
+  const diff = dow === 0 ? -6 : 1 - dow
+  day.setDate(day.getDate() + diff)
+  day.setHours(0, 0, 0, 0)
+  return day
+}
+
+function addDays(d, n) {
+  const r = new Date(d)
+  r.setDate(r.getDate() + n)
+  return r
+}
+
+function toLocalDateStr(d) {
+  return d.toISOString().slice(0, 10)
+}
+
+function fmtShortDate(iso) {
+  if (!iso) return ''
+  const d = new Date(iso + 'T00:00:00')
+  return d.toLocaleDateString('el-GR', { day: '2-digit', month: '2-digit' })
+}
+
+function fmtTime(t) {
+  if (!t) return '—'
+  return t.slice(0, 5)
+}
+
+function durationLabel(h) {
+  if (!h) return ''
+  const hrs = Math.floor(h)
+  const mins = Math.round((h - hrs) * 60)
+  if (hrs === 0) return `${mins}λ`
+  if (mins === 0) return `${hrs}ω`
+  return `${hrs}ω${mins}λ`
+}
+
+// ── Shift slot in cell ────────────────────────────────────────────────────────
+
+function ShiftSlot({ shift, actual, onDelete }) {
+  const hasActual = actual && actual.length > 0
+  const isActive = actual?.some(a => a.is_active)
+
+  return (
+    <div style={{
+      borderRadius: 7, overflow: 'hidden',
+      border: `1.5px solid ${hasActual ? '#86efac' : '#bfdbfe'}`,
+      background: hasActual ? '#f0fdf4' : '#eff6ff',
+      fontSize: 11.5,
+    }}>
+      {/* Scheduled row */}
+      <div style={{ padding: '5px 8px', display: 'flex', alignItems: 'center', justifyContent: 'space-between', gap: 4 }}>
+        <span style={{ fontWeight: 700, color: '#1d4ed8', whiteSpace: 'nowrap' }}>
+          {fmtTime(shift.start_time)}–{fmtTime(shift.end_time)}
+        </span>
+        <div style={{ display: 'flex', alignItems: 'center', gap: 4 }}>
+          {shift.estimated_pay != null && (
+            <span style={{ color: '#6b7280', fontSize: 10.5 }}>{fmt(shift.estimated_pay)}</span>
+          )}
+          <button
+            onClick={() => onDelete(shift.id)}
+            style={{ fontSize: 10, color: '#9ca3af', background: 'none', border: 'none', cursor: 'pointer', padding: '0 2px', lineHeight: 1 }}
+          >
+            ✕
+          </button>
+        </div>
+      </div>
+
+      {/* Actual row */}
+      {hasActual ? (
+        actual.map(a => (
+          <div key={a.id} style={{
+            padding: '3px 8px', borderTop: '1px solid #bbf7d0',
+            fontSize: 10.5, color: '#15803d', fontWeight: 600,
+          }}>
+            ✓ {a.started_at ? new Date(a.started_at).toLocaleTimeString('el-GR', { hour: '2-digit', minute: '2-digit' }) : '—'}
+            {a.ended_at
+              ? ` – ${new Date(a.ended_at).toLocaleTimeString('el-GR', { hour: '2-digit', minute: '2-digit' })}`
+              : isActive ? ' (ενεργή)' : ''}
+          </div>
+        ))
+      ) : (
+        <div style={{ padding: '3px 8px', borderTop: '1px solid #bfdbfe', fontSize: 10.5, color: '#94a3b8' }}>
+          Δεν ξεκίνησε
+        </div>
+      )}
+    </div>
+  )
+}
+
+// ── Add shift modal ───────────────────────────────────────────────────────────
+
+function AddShiftModal({ date, waiters, onClose, onAdd, isPending }) {
+  const [userId, setUserId] = useState(waiters[0]?.id ?? '')
+  const [start, setStart] = useState('09:00')
+  const [end, setEnd] = useState('17:00')
+  const [notes, setNotes] = useState('')
+
+  const inputStyle = {
+    width: '100%', padding: '7px 10px', border: '1px solid #e5e7eb',
+    borderRadius: 7, fontSize: 13, outline: 'none', fontFamily: 'inherit',
+  }
+
+  const canAdd = userId && start && end
+
+  return (
+    <div style={{ position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.45)', display: 'flex', alignItems: 'center', justifyContent: 'center', zIndex: 50, padding: 20 }}>
+      <div style={{ background: 'white', borderRadius: 14, width: '100%', maxWidth: 420, boxShadow: '0 20px 60px rgba(0,0,0,0.18)' }}>
+        <div style={{ padding: '16px 20px 12px', borderBottom: '1px solid #f0f0ef', display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+          <div>
+            <div style={{ fontSize: 15, fontWeight: 700 }}>Νέα Βάρδια</div>
+            <div style={{ fontSize: 12, color: '#6b7280', marginTop: 1 }}>{fmtShortDate(date)}</div>
+          </div>
+          <button onClick={onClose} style={{ background: 'none', border: 'none', fontSize: 18, cursor: 'pointer', color: '#9ca3af' }}>✕</button>
+        </div>
+        <div style={{ padding: '16px 20px', display: 'flex', flexDirection: 'column', gap: 12 }}>
+          <div>
+            <label style={{ fontSize: 11.5, fontWeight: 600, color: '#374151', display: 'block', marginBottom: 4 }}>Σερβιτόρος</label>
+            <select style={inputStyle} value={userId} onChange={e => setUserId(e.target.value)}>
+              {waiters.map(w => <option key={w.id} value={w.id}>{w.name}</option>)}
+            </select>
+          </div>
+          <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 10 }}>
+            <div>
+              <label style={{ fontSize: 11.5, fontWeight: 600, color: '#374151', display: 'block', marginBottom: 4 }}>Έναρξη</label>
+              <input type="time" style={inputStyle} value={start} onChange={e => setStart(e.target.value)} />
+            </div>
+            <div>
+              <label style={{ fontSize: 11.5, fontWeight: 600, color: '#374151', display: 'block', marginBottom: 4 }}>Λήξη</label>
+              <input type="time" style={inputStyle} value={end} onChange={e => setEnd(e.target.value)} />
+            </div>
+          </div>
+          <div>
+            <label style={{ fontSize: 11.5, fontWeight: 600, color: '#374151', display: 'block', marginBottom: 4 }}>Σημείωση <span style={{ fontWeight: 400, color: '#9ca3af' }}>(προαιρετική)</span></label>
+            <input style={inputStyle} value={notes} onChange={e => setNotes(e.target.value)} placeholder="π.χ. Μόνο βράδυ" />
+          </div>
+        </div>
+        <div style={{ padding: '12px 20px', borderTop: '1px solid #f0f0ef', display: 'flex', justifyContent: 'flex-end', gap: 8 }}>
+          <button onClick={onClose} style={{ padding: '7px 16px', border: '1px solid #e5e7eb', background: 'white', borderRadius: 7, fontSize: 13, cursor: 'pointer' }}>Ακύρωση</button>
+          <button
+            onClick={() => onAdd({ user_id: Number(userId), scheduled_date: date, start_time: start, end_time: end, notes: notes || null })}
+            disabled={!canAdd || isPending}
+            style={{ padding: '7px 18px', border: 'none', borderRadius: 7, fontSize: 13, fontWeight: 600, cursor: canAdd ? 'pointer' : 'default', background: canAdd ? '#111827' : '#e5e7eb', color: canAdd ? 'white' : '#9ca3af' }}
+          >
+            {isPending ? 'Αποθήκευση…' : 'Προσθήκη'}
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}
+
+// ── Main page ─────────────────────────────────────────────────────────────────
+
+export default function SchedulePage() {
+  const qc = useQueryClient()
+  const [weekAnchor, setWeekAnchor] = useState(() => weekMonday(new Date()))
+  const [addModal, setAddModal] = useState(null)  // date string | null
+
+  const weekStartStr = toLocalDateStr(weekAnchor)
+  const weekEndStr = toLocalDateStr(addDays(weekAnchor, 6))
+
+  const { data, isLoading } = useQuery({
+    queryKey: ['schedule-week', weekStartStr],
+    queryFn: () => client.get('/api/schedule/week', { params: { week_start: weekStartStr } }).then(r => r.data),
+    staleTime: 30_000,
+  })
+
+  const addShift = useMutation({
+    mutationFn: (body) => client.post('/api/schedule/', body),
+    onSuccess: () => { qc.invalidateQueries({ queryKey: ['schedule-week'] }); setAddModal(null); toast.success('Βάρδια προστέθηκε') },
+    onError: () => toast.error('Σφάλμα αποθήκευσης'),
+  })
+
+  const deleteShift = useMutation({
+    mutationFn: (id) => client.delete(`/api/schedule/${id}`),
+    onSuccess: () => { qc.invalidateQueries({ queryKey: ['schedule-week'] }); toast.success('Βάρδια διαγράφηκε') },
+    onError: () => toast.error('Σφάλμα διαγραφής'),
+  })
+
+  const waiters = data?.waiters ?? []
+  const scheduled = data?.scheduled ?? []
+  const totalPay = data?.total_estimated_pay ?? 0
+
+  // Build lookup: waiter_id → name
+  const waiterNames = Object.fromEntries(waiters.map(w => [w.id, w.name]))
+
+  // Build 7 day columns
+  const days = Array.from({ length: 7 }, (_, i) => {
+    const d = addDays(weekAnchor, i)
+    return { date: d, dateStr: toLocalDateStr(d), label: DAY_LABELS[i] }
+  })
+
+  // Build per-waiter per-day grid
+  // { waiter_id: { dateStr: { scheduled: [...], actual: [...] } } }
+  const grid: Record<number, Record<string, { scheduled: any[], actual: any[] }>> = {}
+
+  for (const s of scheduled) {
+    if (!grid[s.user_id]) grid[s.user_id] = {}
+    const ds = typeof s.scheduled_date === 'string' ? s.scheduled_date : toLocalDateStr(new Date(s.scheduled_date))
+    if (!grid[s.user_id][ds]) grid[s.user_id][ds] = { scheduled: [], actual: [] }
+    grid[s.user_id][ds].scheduled.push(s)
+    grid[s.user_id][ds].actual.push(...(s.actual_shifts || []))
+  }
+
+  // Unique waiter ids that appear in this week's schedule
+  const activeWaiterIds = [...new Set(scheduled.map(s => s.user_id))]
+
+  return (
+    <div style={{ display: 'flex', flexDirection: 'column', height: '100%', overflow: 'hidden' }}>
+      {/* Header */}
+      <div style={{ padding: '14px 24px 12px', borderBottom: '1px solid #f0f0ef', flexShrink: 0, background: 'white', display: 'flex', alignItems: 'center', justifyContent: 'space-between', flexWrap: 'wrap', gap: 10 }}>
+        <div>
+          <h1 style={{ margin: 0, fontSize: 20, fontWeight: 800, color: '#111315' }}>Πρόγραμμα</h1>
+          <p style={{ margin: '2px 0 0', fontSize: 13, color: '#9ca3af' }}>
+            {fmtShortDate(weekStartStr)} – {fmtShortDate(weekEndStr)}
+            {totalPay > 0 && <span style={{ marginLeft: 10, color: '#6b7280' }}>Εκτιμώμενο κόστος εβδομάδας: <strong style={{ color: '#111315' }}>{fmt(totalPay)}</strong></span>}
+          </p>
+        </div>
+        <div style={{ display: 'flex', gap: 8 }}>
+          <button onClick={() => setWeekAnchor(w => addDays(w, -7))}
+            style={{ padding: '6px 14px', border: '1px solid #e5e7eb', background: 'white', borderRadius: 7, fontSize: 13, cursor: 'pointer' }}>← Προηγ.</button>
+          <button onClick={() => setWeekAnchor(weekMonday(new Date()))}
+            style={{ padding: '6px 14px', border: '1px solid #e5e7eb', background: 'white', borderRadius: 7, fontSize: 13, cursor: 'pointer' }}>Αυτή η εβδομάδα</button>
+          <button onClick={() => setWeekAnchor(w => addDays(w, 7))}
+            style={{ padding: '6px 14px', border: '1px solid #e5e7eb', background: 'white', borderRadius: 7, fontSize: 13, cursor: 'pointer' }}>Επόμ. →</button>
+        </div>
+      </div>
+
+      {/* Grid */}
+      <div style={{ flex: 1, overflowX: 'auto', overflowY: 'auto', padding: '12px 24px 16px' }}>
+        {isLoading && <div style={{ color: '#9ca3af', fontSize: 13, textAlign: 'center', padding: '48px 0' }}>Φόρτωση…</div>}
+        {!isLoading && (
+          <table style={{ borderCollapse: 'collapse', width: '100%', minWidth: 700 }}>
+            <thead>
+              <tr>
+                <th style={{ padding: '8px 12px', textAlign: 'left', fontSize: 12, fontWeight: 700, color: '#9ca3af', width: 140 }}>Σερβιτόρος</th>
+                {days.map(d => {
+                  const isToday = toLocalDateStr(new Date()) === d.dateStr
+                  return (
+                    <th key={d.dateStr} style={{
+                      padding: '8px 4px', textAlign: 'center', fontSize: 12,
+                      fontWeight: isToday ? 800 : 600,
+                      color: isToday ? '#3b82f6' : '#374151',
+                      minWidth: 110,
+                    }}>
+                      <div>{d.label}</div>
+                      <div style={{ fontSize: 11, fontWeight: 500, color: isToday ? '#3b82f6' : '#9ca3af' }}>
+                        {fmtShortDate(d.dateStr)}
+                      </div>
+                    </th>
+                  )
+                })}
+              </tr>
+            </thead>
+            <tbody>
+              {/* Rows for scheduled waiters */}
+              {activeWaiterIds.length === 0 && (
+                <tr>
+                  <td colSpan={8} style={{ textAlign: 'center', color: '#d1d5db', fontSize: 13, padding: '40px 0' }}>
+                    Δεν υπάρχουν προγραμματισμένες βάρδιες αυτή την εβδομάδα.<br />
+                    Κάντε κλικ σε ένα κελί για να προσθέσετε.
+                  </td>
+                </tr>
+              )}
+              {activeWaiterIds.map(uid => {
+                const w = waiters.find(w => w.id === uid) || { id: uid, name: waiterNames[uid] || `#${uid}`, hourly_rate: null }
+                return (
+                  <tr key={uid} style={{ borderTop: '1px solid #f3f4f6' }}>
+                    <td style={{ padding: '8px 12px', verticalAlign: 'top' }}>
+                      <div style={{ fontSize: 13, fontWeight: 700, color: '#111315' }}>{w.name}</div>
+                      {w.hourly_rate && <div style={{ fontSize: 11, color: '#9ca3af' }}>{fmt(w.hourly_rate)}/ώρα</div>}
+                    </td>
+                    {days.map(d => {
+                      const cell = grid[uid]?.[d.dateStr]
+                      return (
+                        <td key={d.dateStr} style={{ padding: '4px', verticalAlign: 'top', position: 'relative' }}
+                          onClick={() => { if (!cell?.scheduled?.length) setAddModal({ date: d.dateStr, userId: uid }) }}
+                        >
+                          <div style={{ minHeight: 48, cursor: cell?.scheduled?.length ? 'default' : 'pointer' }}>
+                            {cell?.scheduled?.map(s => (
+                              <ShiftSlot
+                                key={s.id} shift={s}
+                                actual={cell.actual}
+                                onDelete={id => { if (window.confirm('Διαγραφή βάρδιας;')) deleteShift.mutate(id) }}
+                              />
+                            ))}
+                            {!cell?.scheduled?.length && (
+                              <div style={{
+                                height: 48, display: 'flex', alignItems: 'center', justifyContent: 'center',
+                                color: '#e5e7eb', fontSize: 18, borderRadius: 7,
+                                border: '1.5px dashed transparent',
+                              }}
+                                onMouseEnter={e => e.currentTarget.style.borderColor = '#bfdbfe'}
+                                onMouseLeave={e => e.currentTarget.style.borderColor = 'transparent'}
+                              >
+                                +
+                              </div>
+                            )}
+                          </div>
+                        </td>
+                      )
+                    })}
+                  </tr>
+                )
+              })}
+
+              {/* Add row for other waiters not yet scheduled */}
+              <tr style={{ borderTop: '1px solid #f3f4f6' }}>
+                <td colSpan={8} style={{ padding: '8px 12px' }}>
+                  <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
+                    {waiters.filter(w => !activeWaiterIds.includes(w.id)).map(w => (
+                      <button key={w.id}
+                        onClick={() => setAddModal({ date: weekStartStr, userId: w.id })}
+                        style={{
+                          padding: '4px 12px', fontSize: 12, fontWeight: 600, cursor: 'pointer',
+                          border: '1px dashed #d1d5db', borderRadius: 20, background: 'white', color: '#6b7280',
+                        }}>
+                        + {w.name}
+                      </button>
+                    ))}
+                    {waiters.length === 0 && (
+                      <span style={{ fontSize: 12, color: '#d1d5db' }}>Δεν υπάρχουν ενεργοί σερβιτόροι.</span>
+                    )}
+                  </div>
+                </td>
+              </tr>
+            </tbody>
+          </table>
+        )}
+      </div>
+
+      {/* Legend */}
+      <div style={{ padding: '8px 24px', borderTop: '1px solid #f0f0ef', background: '#fafafa', display: 'flex', gap: 16, flexShrink: 0 }}>
+        {[
+          { color: '#bfdbfe', bg: '#eff6ff', label: 'Προγραμματισμένη (δεν ξεκίνησε)' },
+          { color: '#86efac', bg: '#f0fdf4', label: 'Προγραμματισμένη + Πραγματική' },
+        ].map(l => (
+          <div key={l.label} style={{ display: 'flex', alignItems: 'center', gap: 6, fontSize: 11.5, color: '#6b7280' }}>
+            <div style={{ width: 14, height: 10, borderRadius: 3, background: l.bg, border: `1.5px solid ${l.color}` }} />
+            {l.label}
+          </div>
+        ))}
+      </div>
+
+      {addModal && (
+        <AddShiftModal
+          date={addModal.date}
+          waiters={addModal.userId
+            ? waiters.filter(w => w.id === addModal.userId).concat(waiters.filter(w => w.id !== addModal.userId))
+            : waiters}
+          onClose={() => setAddModal(null)}
+          isPending={addShift.isPending}
+          onAdd={(body) => addShift.mutate(body)}
+        />
+      )}
+    </div>
+  )
+}