[pull] master from supabase:master - #1125

## Summary

- Move High Availability into the standard project creation settings
above Compute, gated by the `instances.high_availability` entitlement.
- Mark the option as Alpha and explain that it is free during Alpha for
up to two projects.
- Enforce the supported HA configuration: `AWS_K8S`, Postgres 17 on the
`ga` release channel (no custom version is sent — the API resolves the
image), and the environment-specific local/staging region restrictions.
- Show eligible locations in a dedicated **High Availability Regions**
group.
- Preserve the existing Advanced Configuration availability rules and
additionally hide the section while HA is enabled.
- Restore the previous provider and Postgres settings when HA is
switched off.

## How to test
1. Go to create a new project
2. Ensure you have access to high availability (e.g. on local)
3. Toggle high availability on and note how the project form restricts
settings listed above

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added High Availability to project creation with Alpha warning
labeling and improved switch accessibility.
* Constrains region selection to compatible High Availability regions
and enforces HA-specific engine/release settings.
* Disables/hides custom PostgreSQL version selection when High
Availability is enabled (and omits HA custom request payloads).

* **Bug Fixes**
* Improved persistence of selected PostgreSQL version and region across
data reloads and configuration panel reopen/toggle.
* Restores region when form state temporarily drops values during
remounts.

* **Tests**
* Expanded end-to-end coverage for HA UI, region grouping, and
submit/payload restoration behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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Co-authored-by: Alaister Young <10985857+alaister@users.noreply.github.com>
Co-authored-by: Joshen Lim <joshenlimek@gmail.com>

## 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 -->

- Updates connection pooling settings to be read-only when a high
availability project with ip4 admonition removed
- Updates organization usage to be disabled until supported
- Updates database publications to be disabled until supported

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added High Availability handling for database publications, usage, and
connection pooling.
* Publications and usage now display dedicated “unavailable” empty
states and hide gated content when High Availability is enabled.
* Connection pooling switches to managed/read-only mode on High
Availability, disabling edits and form submission and disabling related
data fetching.
  * Pooling mode controls are hidden on High Availability.
* **Refactor**
* Refactored database publications pages by extracting main rendering
logic into internal components.
* **Tests**
* Added Vitest + React Testing Library coverage for High Availability
behavior across publications availability, usage, connection pooling,
and pooling modes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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Co-authored-by: Alaister Young <10985857+alaister@users.noreply.github.com>