Fix networkConnect() and networkDisconnect() to send valid options

[clue]

This changeset fixes networkConnect() and networkDisconnect() to send valid options. Passing $endpointConfig or $force previously made Docker reject the request with 400 Bad Request, because the endpoint config was sent as a JSON string instead of an object and Force was sent as 1 instead of a boolean. Both have been broken since they were added in #57 (2020), so this is the first release where either option works. The functional tests now cover both options against a real Docker daemon.

Builds on top of #57

[Copilot]

🟢 Approval recommended

The focused fixes have targeted regression coverage and no unresolved findings; tests were not executed.

No open issues 🎉

What changed in this PR

Fixes network option serialization so Docker receives endpoint configuration as an object and Force as a boolean.

Changes:

• Removes double encoding of endpoint configuration.
• Sends a boolean for forced disconnection.
• Adds unit regression coverage and exercises both options in functional tests.

File	Description
tests/​FunctionalClientTest.php	Exercises network aliases and forced disconnection.
tests/​ClientTest.php	Verifies serialized option values.
src/​Client.php	Corrects network request serialization.

_{Review effort: Balanced}