chore: switch replay commands to SDK endpoints - #482

## Motivation

Replay clients currently maintain separate HTTP requests and models. A
versioned SDK interface provides one public contract for managing
Replays and reduces drift between consumers.

## Summary

- Added Replay V1 methods to run Replays, list active requests, inspect
status, request cancellation, delete queued requests, and check
availability.
- Added validated requests and typed response values for Replay types,
statuses, cancellation states, sources, durations, and availability
reasons.
- Preserved RFC3339 `createdAt` values and unknown availability reasons
returned by the Nobl9 platform.
- Required availability requests to select either an SLO or a data
source and rejected non-positive or overflowing durations without
reintroducing the former 30-day SDK limit.
- Replaced the legacy `sdk/models` Replay API with
`sdk/endpoints/replay/v1`.

## Related changes

- [sloctl #482](nobl9/sloctl#482)

## Testing

- Added end-to-end coverage for availability by SLO and data source,
`timeRange.startDate`, source-SLO objective mapping, and `Run`, `List`,
`GetStatus`, `Cancel`, and `Delete` flows, including queued,
in-progress, canceled, and completed states plus RFC3339 `createdAt`.
- Added unit coverage for request validation and serialization, selector
modes, duration boundaries and overflow, status conversion, and unknown
availability reasons.

## Release Notes

Added a versioned Replay API to start Replays, inspect status and
availability, list active requests, request cancellation, and delete
queued requests. Replay types now live under `sdk/endpoints/replay/v1`.

## Breaking Changes

Removed the `sdk/models` package, including its legacy Replay types and
helpers. Consumers must migrate to `sdk/endpoints/replay/v1`.
`models.Replay` is replaced by `v1.RunRequest`, acronym fields use
`SLO`, and the unsupported `EndDate` field has no replacement.