feat(agents): introduce TechAIPairArchitectAnalysisExecutor and enhance customization workflows

[diegoitaliait]

Description

Add the TechAIPairArchitectAnalysisExecutor for validated execution planning and improve the clarity and functionality of customization agents and skills. Update naming conventions and enhance documentation for better usability.

Change Type

• Agent update
• Instruction update
• Skill update
• Workflow/automation update
• Validation script update
• Documentation/configuration only
• Other

List of changes

• Introduced TechAIPairArchitectAnalysisExecutor for execution planning.
• Refactored agent and skill names for clarity.
• Enhanced documentation and usage guidelines.

Consumer Impact

• Affected customization assets: TechAIPairArchitectAnalysisExecutor, TechAIStandardsRepoConfigAuditor, TechAISyncGlobalCopilotConfigsIntoRepo, TechAIPREditor, TechAIRepoCopilotExtender.
• Backward compatibility notes: Updated agent names may require adjustments in existing workflows.
• Rollout or migration notes (if any): Ensure all references to deprecated agents are updated.

Testing Instructions

1. Validate the execution planning with the new TechAIPairArchitectAnalysisExecutor.
2. Test the updated agents and skills for expected functionality.

Validation Evidence

• Customization validator result: Pending validation.
• Stack-specific checks/tests result: Pending tests.
• Security/supply-chain checks result: Pending checks.

Breaking Changes

• This PR contains breaking changes
• The renaming of agents may affect existing workflows that reference the old names.

Checklist

• No secrets/tokens/credentials committed
• Repository artifacts remain in English
• validate-copilot-customizations.sh --mode strict executed successfully
• Workflow action pins use full SHA with adjacent release/tag reference
• References remain repository-agnostic and reusable