v2.5.7: Reservation overhaul, Day Detail Panel, i18n, paste support, auto dark mode

BREAKING: Reservations have been completely rebuilt. Existing place-level
reservations are no longer used. All reservations must be re-created via
the Bookings tab. Your trips, places, and other data are unaffected.

Reservation System (rebuilt from scratch):
- Reservations now link to specific day assignments instead of places
- Same place on different days can have independent reservations
- New assignment picker in booking modal (grouped by day, searchable)
- Removed day/place dropdowns from booking form
- Reservation badges in day plan sidebar with type-specific icons
- Reservation details in place inspector (only for selected assignment)
- Reservation summary in day detail panel

Day Detail Panel (new):
- Opens on day click in the sidebar
- Detailed weather: hourly forecast, precipitation, wind, sunrise/sunset
- Historical climate averages for dates beyond 16 days
- Accommodation management with check-in/check-out, confirmation number
- Hotel assignment across multiple days with day range picker
- Reservation overview for the day

Places:
- Places can now be assigned to the same day multiple times
- Start time + end time fields (replaces single time field)
- Map badges show multiple position numbers (e.g. "1 · 4")
- Route optimization fixed for duplicate places
- File attachments during place editing (not just creation)
- Cover image upload during trip creation (not just editing)
- Paste support (Ctrl+V) for images in trip, place, and file forms

Internationalization:
- 200+ hardcoded German strings translated to i18n (EN + DE)
- Server error messages in English
- Category seeds in English for new installations
- All planner, register, photo, packing components translated

UI/UX:
- Auto dark mode (follows system preference, configurable in settings)
- Navbar toggle switches light/dark (overrides auto)
- Sidebar minimize buttons z-index fixed
- Transport mode selector removed from day plan
- CustomSelect supports grouped headers (isHeader option)
- Optimistic updates for day notes (instant feedback)
- Booking cards redesigned with type-colored headers and structured details

Weather:
- Wind speed in mph when using Fahrenheit setting
- Weather description language matches app language

Admin:
- Weather info panel replaces OpenWeatherMap key input
- "Recommended" badge styling updated

client/src/components/PDF/TripPDF.jsx

@@ -144,9 +144,6 @@ export async function downloadTripPDF({ trip, days, places, assignments, categor
           const googleImg = photoMap[place.id] || null
           const img = directImg || googleImg
 
-          const confirmed = place.reservation_status === 'confirmed'
-          const pending   = place.reservation_status === 'pending'
-
           const iconSvg = categoryIconSvg(cat?.icon, color, 24)
           const thumbHtml = img
             ? `<img class="place-thumb" src="${escHtml(img)}" />`
@@ -157,8 +154,6 @@ export async function downloadTripPDF({ trip, days, places, assignments, categor
           const chips = [
             place.place_time ? `<span class="chip">${svgClock}${escHtml(place.place_time)}</span>` : '',
             place.price && parseFloat(place.price) > 0 ? `<span class="chip chip-green">${svgEuro}${Number(place.price).toLocaleString('de-DE')} EUR</span>` : '',
-            confirmed ? `<span class="chip chip-green">${svgCheck}${escHtml(tr('reservations.confirmed'))}</span>` : '',
-            pending   ? `<span class="chip chip-amber">${svgClock2}${escHtml(tr('reservations.pending'))}</span>` : '',
           ].filter(Boolean).join('')
 
           return `
@@ -352,7 +347,7 @@ export async function downloadTripPDF({ trip, days, places, assignments, categor
       ? `<div class="cover-circle"><img src="${escHtml(coverImg)}" /></div>`
       : `<div class="cover-circle-ph"></div>`}
     <div class="cover-label">${escHtml(tr('pdf.travelPlan'))}</div>
-    <div class="cover-title">${escHtml(trip?.title || 'Meine Reise')}</div>
+    <div class="cover-title">${escHtml(trip?.title || 'My Trip')}</div>
     ${trip?.description ? `<div class="cover-desc">${escHtml(trip.description)}</div>` : ''}
     ${range ? `<div class="cover-dates">${range}</div>` : ''}
     <div class="cover-line"></div>