bug: The wp, exec and logs commands do not accept flags for the container #4

Blocker: yes. Fix this before the server-monitoring work starts.

Defect

Test results:

• fly wp plugin list --format=json shows Error: unknown flag: --format.
• fly exec php ls -la shows Error: unknown shorthand flag: 'l' in -la.
• fly logs -f shows unknown shorthand flag: 'f'.
• fly logs -- -f follows the logs of all containers. The README does not show this.
• fly logs -- -f php shows accepts at most 1 arg(s). Thus, a user cannot follow the logs of one container.
• -- is a workaround for wp and exec. The README does not show it.

Related defect:

• fly exec <cmd> uses the php service by default (cmd/site.go:108). OpenLiteSpeed sites do not have a php service.
• Pull request Fix(ols): Fix cli not detecting OLS sites #1 corrected the service detection for wp only.

Cost

• WP-CLI is the most frequent daily task. Most WP-CLI commands with flags do not operate.
• Users must know about --. The documentation does not tell them.
• During an incident, users cannot follow the logs of one container.
• On OpenLiteSpeed sites, fly exec without a service name does not operate.

Benefit of the fix

• WP-CLI and container commands operate with their usual flags.
• Users can follow the logs of one container.
• fly exec operates on PHP sites and on OpenLiteSpeed sites.

Fix

1. Call Flags().SetInterspersed(false) on wp and exec. Then, all arguments after the first positional argument go to the container. --domain must come before them.
2. For logs, add -f/--follow and --tail. As an alternative, send the arguments to Docker Compose without change.
3. For exec, select the default service with the same detection as wp (getContainerName).

Completion checks

• The first three commands in "Defect" operate.
• fly --domain example.com wp plugin list --format=json operates.
• fly exec ls on an OpenLiteSpeed site uses the openlitespeed service.
• Tests for these items.