## What kind of change does this PR introduce?
Feature, limited to staging and local.
## What is the current behavior?
On High Availability projects, Studio always disables Realtime: the
Realtime pages and the Publications pages show an "unavailable" message,
the table editor's "Enable Realtime" checkbox is disabled, and the
project home shows Realtime as disabled.
## What is the new behavior?
A new `useIsRealtimeUnavailable()` hook treats Realtime as unavailable
only on High Availability projects outside staging and local (via
`IS_STAGING_OR_LOCAL`). Those four places use it instead of checking
`high_availability` directly.
- **Production:** unchanged.
- **Staging and local:** Realtime behaves as on standard projects.
## Additional context
Whether a High Availability project is actually registered as a Realtime
tenant is gated separately on the platform side. Until then, the pages
render but Realtime connections for that project fail.
Tests: a new `resolveRealtimeUnavailable` test, and the
`TableRealtimeToggle` and `resolveRealtimeServiceStatus` tests updated
for the renamed parameter.
## Summary
More gating to support upcoming High Availability projects.
- Keep the Recent Branch stat visible on the project home page for HA
projects, but disable its interaction, reduce its opacity, and skip the
branches query.
- Treat Realtime as disabled for HA projects in the service-status
dropdown so it does not make the project appear unhealthy or trigger
unhealthy polling.
- Show the shared unsupported-feature empty state for Custom Domains and
skip its query on HA projects.
- Disable the Enable Realtime checkbox in the table creation sheet for
HA projects.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **New Features**
- Added High Availability–aware behavior across activity stats, service
status, custom domains, and table realtime controls.
- Introduced reusable Branch value UI that shows an “Unavailable” state
in High Availability mode.
- Added a dedicated realtime toggle UI that disables interaction and
updates helper text when unavailable.
- **Bug Fixes**
- Ensured realtime is treated as disabled (not unhealthy) in High
Availability and prevented realtime enabling/saving.
- Reduced unnecessary data fetching by gating addon/custom-domain
requests and disabling branch queries.
- **Tests**
- Added coverage for realtime status resolution, BranchStatValue
“Unavailable” rendering, and TableRealtimeToggle behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Ping-Min Lin