InternalRunService: silent data loss when RecordAction fails before UpdateActionStatus

## Summary

When the Actions Service's TaskAction CRD watcher (`actions/k8s/client.go:notifyRunService`) fails to call `InternalRunService.RecordAction`, subsequent `UpdateActionStatus` calls for the same action **silently no-op** — the gRPC response is success, but zero rows are updated and the action is effectively invisible in the Runs DB until a K8s watch re-list re-emits `ADDED`.

## Reproduction

1. Runs Service is briefly unavailable when a TaskAction's `ADDED` event is processed.
2. `RecordAction` fails. The Actions Service logs a `Warnf` and moves on (no retry). The bloom filter is **not** updated, but no further action is taken.
3. Runs Service recovers.
4. Subsequent `MODIFIED` events for that TaskAction call `UpdateActionStatus`. The SQL `UPDATE` matches zero rows. Runs Service returns `nil` error (see `runs/repository/impl/action.go:397-416`, `runs/service/internal_run_service.go:232`).
5. The action never appears to clients using `WatchRunDetails` until a watch re-list occurs (controller restart / watcher reconnect).

## Root cause

Two coupled issues in `InternalRunService`:

1. **`UpdateActionPhase` returns success on 0 rows affected.** The caller has no way to know the action is missing from the DB.
2. **`RecordAction` and `UpdateActionStatus` are split RPCs.** The client must call both in order; there is no single idempotent "report" operation.

## Proposed fix

**1. Make `UpdateActionStatus` return `NotFound` when no row is matched.**

```go
// runs/repository/impl/action.go
if rowsAffected == 0 {
return ErrActionNotFound
}
```

…mapped to `connect.CodeNotFound` in the gRPC handler.

**2. Add `ActionStatus status = 6` to `RecordActionRequest`** so the initial insert carries the correct phase (no transient `PHASE_UNSPECIFIED` window).

**3. Self-heal in `actions/k8s/client.go:notifyRunService`:**

```go
_, err := c.runClient.UpdateActionStatus(ctx, statusReq)
if connect.CodeOf(err) == connect.CodeNotFound {
// Row missing — RecordAction must have failed earlier. Rebuild from CRD
// and re-record. Follow the existing pattern: Add to the bloom filter only
// on success (the filter is add-only; never Remove).
recordReq := buildRecordRequestFromCRD(taskAction)
if _, recErr := c.runClient.RecordAction(ctx, recordReq); recErr == nil {
if c.recordedFilter != nil {
c.recordedFilter.Add(ctx, actionKey)
}
// Optional: retry UpdateActionStatus now that the row exists.
}
}
```

The Actions Service still has the TaskAction CRD in its informer cache, so rebuilding the `RecordActionRequest` is free.

**4. On `ADDED` events, skip the separate `UpdateActionStatus`** — `RecordAction` now carries the status.

### Independent improvements

- **Bounded retry with backoff** for transient errors (`Unavailable`, `DeadlineExceeded`) — 3 attempts, exponential (100ms / 500ms / 2s). Don't block the sharded worker on long outages.
- **Periodic reconciliation sweep** — every ~5min list TaskAction CRDs without the `flyte.org/terminal-status-recorded` label and force a `notifyRunService` pass. Backstop for cases where the watcher doesn't reconnect but Runs Service has recovered.

## References

- `actions/k8s/client.go:554-646` — `notifyRunService`
- `runs/service/internal_run_service.go:191-255` — `UpdateActionStatus` handler
- `runs/repository/impl/action.go:361-417` — `UpdateActionPhase` (the silent-success site)