refactor: route Taxonomy CLI through registered abilities

[chubes4]

Goal

Complete the Taxonomy CLI adapter convergence by removing direct concrete ability construction from TaxonomyCommand and executing the already registered WordPress abilities through the existing CLI AbilityRunner.

Refs #3332. Parent: #3113.

Scope

Update inc/Cli/Commands/TaxonomyCommand.php to execute:

• datamachine/get-taxonomy-terms
• datamachine/create-taxonomy-term
• datamachine/update-taxonomy-term
• datamachine/delete-taxonomy-term
• datamachine/resolve-term

The list command already establishes the AbilityRunner pattern. Remove the five concrete Taxonomy ability imports. Do not modify ability implementations.

Contract preservation

Preserve exactly:

• command names and aliases
• positional arguments, options, defaults, casts, and optional-field inclusion
• all preflight validation messages
• delete confirmation timing and --yes
• JSON, table, CSV, and YAML behavior where supported
• success, warning, log, and error text
• pagination behavior
• WP_CLI::error() exit behavior
• create success-message ordering before optional JSON
• resolve Created versus Resolved presentation

Do not move parsing or presentation into abilities. AbilityRunner may normalize native WP_Error into the existing CLI failure-array path, but public output must not leak diagnostic metadata.

Tests

• Extend AllAbilitiesRegisteredTest with all five Taxonomy slugs.
• Add focused Taxonomy CLI coverage for list defaults/output, create success/failure, update, delete confirmation and --yes, resolve existing/create behavior, and native error normalization.
• Continue running TaxonomyAbilityWpErrorTest.

Constraints

• No helper, wrapper, resolver, framework, DSL, or compatibility infrastructure.
• No ability implementation changes.
• No command or output contract changes.
• Use existing AbilityRunner; do not duplicate raw registry plumbing.
• Keep production PHP net-negative.
• Do not edit CHANGELOG.md or version strings.
• Avoid every file touched by open PR fix: prepare WordPress.org release package #3361.
• Conventional refactor: commit.
• PR only; do not release or deploy.

Expected production delta: approximately -5 PHP LOC.