refactor(bookings): simplify capacity tracking to use seats

Replace 'pax' booking mode with 'seat'
Consolidate inventory summary to track only seat counts
Update database schema and UI for seat-centric capacity

server/utils/db-init.ts

@@ -69,7 +69,7 @@ async function initializeDatabase() {
       receipt_token text not null unique,
       customer_name text not null,
       customer_phone text not null,
-      booking_mode text not null check (booking_mode in ('table', 'pax')),
+      booking_mode text not null check (booking_mode in ('table', 'seat')),
       quantity integer not null check (quantity >= 1),
       seat_count integer not null check (seat_count >= 1),
       ticket_type text not null check (ticket_type in ('vip', 'supporter')),
@@ -124,6 +124,11 @@ async function initializeDatabase() {
     )
   `
 
+  await sql`
+    alter table booking_settings
+    add column if not exists total_seats integer
+  `
+
   await sql`
     insert into booking_settings (id)
     values ('default')
@@ -146,6 +151,45 @@ async function initializeDatabase() {
     `
   }
 
+  await sql`
+    alter table bookings
+    drop constraint if exists bookings_booking_mode_check
+  `
+
+  await sql`
+    alter table bookings
+    add constraint bookings_booking_mode_check
+    check (booking_mode in ('table', 'pax', 'seat'))
+  `
+
+  await sql`
+    update bookings
+    set
+      booking_mode = 'seat',
+      updated_at = now()
+    where booking_mode = 'pax'
+  `
+
+  await sql`
+    alter table bookings
+    drop constraint if exists bookings_booking_mode_check
+  `
+
+  await sql`
+    alter table bookings
+    add constraint bookings_booking_mode_check
+    check (booking_mode in ('table', 'seat'))
+  `
+
+  await sql`
+    update booking_settings
+    set
+      total_seats = total_tables * 10,
+      updated_at = now()
+    where total_seats is null
+      and total_tables is not null
+  `
+
   const existingBookings = await sql<{ id: string, seat_count: number | string }[]>`
     select
       id,