[KazuCocoa]

Change list

Follow-up to #1358. A directConnectPath of "" is a valid root endpoint, but was treated as missing. Preserve it for both capability formats, including when an empty prefixed path overrides a legacy path.

Reuse the existing command executor instead of invoking its constructor again. This preserves subclasses with required constructor arguments, instance state, and registered commands. Copy the client config so the caller's configuration remains unchanged; clear the old HTTP pool, reevaluate proxy selection for the new endpoint, and rebuild the pool when keep-alive is enabled. Read the effective config directly from the executor.

Regression coverage includes root paths, prefixed precedence, custom executor state and commands, both keep-alive settings, and proxy selection/pool cleanup. The root-path and custom-constructor regressions fail on #1358's original implementation.

Validation

• Python 3.14 / Selenium 4.52: all 240 unit tests passed (warnings from the existing test suite).
• ruff check ., ruff format --check ., and mypy appium passed.

Types of changes

• Bugfix
• Unit tests added/updated