Info-exchange homepage + platform support (land EWYAIX)

[rustynwac]

Add an info-exchange homepage for centers that publish observations and host weather stations but don't issue forecasts — landing EWYAIX (Eastern Wyoming Avalanche Info Exchange, ewyoavalanche.org) as the first one.

Instead of the default forecast homepage (forecast copy + upcoming-events block), provisionTenant writes an info-exchange variant: observation-focused copy + an ObservationsWidget block. Everything else below is plumbing to make that homepage reachable and correct. NAC already models these centers (EWYAIX, SOAIX); our schema parsing and "every tenant forecasts" provisioning assumption currently reject them.

Ships as one PR — the EWYAIX seed is the end-to-end test.

Re-scoped 2026-06-11 from the original "add Eastern Idaho" ask (now #1111) after a /grill-me session.

Constraint: no kind/discriminator field. "Info exchange" ≡ !platforms.forecasts && platforms.obs; all visibility is driven by NAC platforms flags.

The homepage variant (centerpiece)

In provisionTenant (src/collections/Tenants/endpoints/provisionTenant.ts), branch on !platforms.forecasts when creating the home page:

• Copy — info-exchange highlightedContent (observation/safety-focused, not "avalanche forecasts, mountain weather conditions").
• Layout — a single observationsWidget block instead of the default eventList block.
• Block — new ObservationsWidget (src/blocks/ObservationsWidget/, slug observationsWidget, no fields): heading + Submit button + <ObservationsDisclaimer /> + <NACWidget widget="observations" />. Register in RenderBlocks.tsx + HomePages layout; migration add_observations_widget_block; regenerate types.

Plumbing to support it

• Schema — relax avalancheCenterSchema (src/services/nac/types/schemas.ts) so info exchanges parse: city nullable, config nullable, add Other = 'other' to AvalancheCenterType. Fixture test: NWAC (full), EWYAIX + SOAIX (nulls).
• Routing — gate homepage <NACWidget widget="warnings" /> (src/app/(frontend)/[center]/page.tsx) on platforms.warnings. Danger map unchanged (info-exchange zones render gray "no rating").
• Other provisioning — when !platforms.forecasts: gate BUILT_IN_PAGES "Weather Stations" on platforms.stations; resolveBuiltInPages skips AFP zones fetch + stale "All Forecasts" fallback; reduced PAGES_TO_PROVISION = About Us, Donate/Membership, Volunteer.
• Tenant — add ewyaix to AVALANCHE_CENTERS (src/utilities/tenancy/avalancheCenters.ts) with customDomain: 'ewyoavalanche.org' (config-only, does not flip DNS — EWY production cutover to NWAC platform #1110); update the stale "excluded" comment.
• Seed — run provisionTenant for ewyaix (prod + pnpm seed).

Acceptance (smoke-check EWYAIX): homepage shows the observations widget, no forecasts/weather nav tabs; /observations, /observations/submit, /weather/stations/map work; /forecasts/avalanche, /weather/forecast 404; admin Pages list has About Us, Donate/Membership, Volunteer.

Follow-ups

• EWY production cutover to NWAC platform #1110 — EWY production DNS cutover.
• Onboard Eastern Idaho Info Exchange #1111 — Onboard Eastern Idaho (post-naming).
• Show surrounding-center forecasts on info-exchange sites #1112 — Surrounding-center forecasts (map + nav).

[stevekuznetsov]

We just turn off the forecasts/weather tabs and show obs + the rest? What else is special about these?

[rustynwac]

That's pretty much it. In this case, they also want to show surrounding forecasts (BTAC, SNFAC, GNFAC, maybe UAC)

[busbyk]

I think the surrounding forecast areas being shown on the map is a widgets feature that will have to be enabled on their end. Do we know if Chris is working on that?

We could pull additional forecast zones for the navigation fairly easily.

[rustynwac]

Lets chat about it at the next check-in. I think it's a minimal lift. They dont even have a name or domain picked out. I told Ethan I'd get him a list of things to think about for his next check-in with their group (week after July 4).

[busbyk]

@rustynwac there doesn't seem to be a good milestone for this.

[rustynwac]

E Idaho will come onboard sometime between now and the fall. Thus we will need to add info exchange functionality. We might need to talk to Ethan but it should be something like this: https://ewyoavalanche.org/#/view/observations

Lets track this work item separately as they have a grant to pay for it.