Add multi-guest management: per-booking roster, docs, guest autocomplete

- Migration 010: booking_guests table (roster per booking with passport data)
- Backend: /bookings/:id/guests CRUD — auto-links/creates guest profiles by passport
- Backend: /hotel-settings GET/PATCH for key-value settings (require_guest_docs)
- BookingDetailPanel: Гости tab with multi-guest list, inline add/edit form,
  guest autocomplete (debounced search in guests table), child/main badges,
  passport fields for adults, scan stub, require-docs warning
- SettingsPage: toggle "Обязательное заполнение документов гостей"
- Pass slug prop through CalendarPage → BookingCalendar → BookingDetailPanel

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

backend/migrations/010_booking_guests.sql

@@ -0,0 +1,28 @@
+-- Migration 010 — booking_guests: per-booking guest roster with documents
+
+CREATE TABLE IF NOT EXISTS booking_guests (
+  id                   UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
+  booking_id           UUID         NOT NULL REFERENCES bookings(id) ON DELETE CASCADE,
+  hotel_id             UUID         NOT NULL REFERENCES hotels(id) ON DELETE CASCADE,
+  guest_id             UUID         REFERENCES guests(id) ON DELETE SET NULL,
+
+  first_name           VARCHAR(100) NOT NULL,
+  last_name            VARCHAR(100) NOT NULL,
+  middle_name          VARCHAR(100),
+
+  birth_date           DATE,
+  is_child             BOOLEAN      NOT NULL DEFAULT false,
+  is_main              BOOLEAN      NOT NULL DEFAULT false,
+
+  passport_series      VARCHAR(20),
+  passport_number      VARCHAR(20),
+  passport_issued_by   TEXT,
+  passport_issue_date  DATE,
+  nationality          VARCHAR(100),
+
+  created_at           TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
+  updated_at           TIMESTAMPTZ  NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_booking_guests_booking ON booking_guests(booking_id);
+CREATE INDEX IF NOT EXISTS idx_booking_guests_guest   ON booking_guests(guest_id);