04-swarms CLI scripts use --name on 'aca sandboxgroup identity/role'; CLI rejects it (must be --group)

## Summary

The CLI swarm scripts call `aca sandboxgroup identity` and `aca sandboxgroup role` with `--name `, but the `aca` CLI only accepts `--group` on those subcommands. As written, the swarm provisioning fails at runtime.

## Evidence (aca 1.0.0-preview.1)

```
$ aca sandboxgroup identity show --name aca-sandboxes-samples
error: unexpected argument '--name' found
Usage: aca sandboxgroup identity show [OPTIONS]

$ aca sandboxgroup identity show --group aca-sandboxes-samples
Error: subscription ID required (use -s or ACA_SUBSCRIPTION) # accepted, proceeds
```

`--help` for `identity assign`, `identity show`, and `role create` lists only `--group `; there is no `--name` flag or alias.

## Affected lines

- `cli/samples/04-swarms/01-sandbox-inception/cli/run.sh`: identity assign (~line 78), identity show (~80), role create (~103-105)
- `cli/samples/04-swarms/02-shared-blob-memory/cli/run.sh`: identity assign (~79), identity show (~81), role create (~99-101)

## Fix

Replace `--name` with `--group` on every `aca sandboxgroup identity ...` and `aca sandboxgroup role ...` invocation in both swarm `run.sh` scripts. Validate by running the script end to end against a real sandbox group.

Inspect cli/samples/04-swarms/01-sandbox-inception/cli/run.sh and cli/samples/04-swarms/02-shared-blob-memory/cli/run.sh at the listed identity and role commands. Compare those invocations with aca sandboxgroup identity and role --help, then run each script against a real sandbox group. Done means both scripts use the accepted group option and complete swarm provisioning without the unexpected-argument error.

Written by the indexing model from the issue text.