Set up a venue, its capacity and its zones

Steps

1. 1 Administrator Open the admin hub 0:07 ▣
2. 2 Administrator Open Venues 0:08 ▣

   The three house rooms were ADOPTED by the migration, not invented by it — Main Warehouse, Blue Room and Mezzanine already existed as strings in `events.venue`.

3. 3 Administrator Start a new venue 0:09
4. 4 Administrator Name the room — the slug derives itself 0:11 ▣

   The slug is PERMANENT. Zone codes are derived from it and every signed ticket carries those codes, so a slug that moved would leave a venue's name and its doors permanently out of step.

5. 5 Administrator Set the fire-code capacity 0:12

   The head-count ceiling: it clamps what a host may ask for on /host/apply and it gates the sum of tier inventory when an event here goes on sale.

6. 6 Administrator Address, clock and house defaults 0:13 ▣

   The timezone is authoritative for every time captured or displayed for an event in this room — the guided run-of-show builder asks the venue, not the browser.

7. 7 Administrator Create the venue 0:14 ▣
8. 8 Administrator Add the Main Floor zone 0:15

   Granting a zone to a group re-issues those members' MEMBERSHIP cards (the superseded ones are revoked). Event-ticket passes are never re-minted by anything in this module — the UI says so above the boxes.

9. 9 Administrator …the code derives itself: …_main 0:16 ▣

   Never client-supplied. `derive_zone_code(venue_slug, suffix)` is the ONLY way a venue zone code is minted, and that is what keeps codes globally unique — the door scanner compares this exact string with no venue in scope, so two rooms both owning `A` would open each other.

10. 10 Administrator Grant it to `member` 0:17
11. 11 Administrator Create the zone 0:18
12. 12 Administrator Add the Backstage zone 0:19

    A second zone, same rule: derived, globally unique, and immutable from the moment it exists.

13. 13 Administrator …the code derives itself: …_backstage 0:20 ▣

    Never client-supplied. `derive_zone_code(venue_slug, suffix)` is the ONLY way a venue zone code is minted, and that is what keeps codes globally unique — the door scanner compares this exact string with no venue in scope, so two rooms both owning `A` would open each other.

14. 14 Administrator Create the zone 0:21
15. 15 Administrator Both zones now belong to the room 0:22 ▣

    `Readers` is module 03's physical inventory: a zone starts with none, and readers are pinned to it separately.

16. 16 Administrator Create an event in the new room 0:24 ▣
17. 17 Administrator Pick the venue 0:25 ▣

    The hint under the picker is the room speaking: its name, its capacity and the timezone that resolved for it.

18. 18 Administrator Name the night and set its slots 0:26
19. 19 Administrator Create the draft event 0:29 ▣
20. 20 Administrator The event carries the ROOM, not a typed string 0:31 ▣

    `events.venue_id` is the binding; `events.venue` survives only as a display mirror the service keeps in step — and freezes on a completed event, because that string is the historical record of where the show happened.

21. 21 Administrator …and the room lists the event 0:32 ▣

    Capacity is a rollup now: the room's ceiling, the sum of its zone capacities, and every event booked into it with its tier inventory.