feat(telemetry): ask who is measured at opt-in, and name the default #1029

Problem to solve

aidd telemetry report --axis person shows a row named absent unless the person ran aidd telemetry identity <id>, a separate command almost nobody finds. The report does not say who was measured, and absent reads like missing data rather than "not named".

Proposed solution

Ask for the identity when it matters, at opt-in, and name the default clearly.

• aidd telemetry on proposes the git user.name (else user.email) as the identity. One line confirms it, edits it or declines it.
• Non-interactive: --as <id> or --anonymous.
• aidd telemetry status says under which name this machine is measured.
• With no identity, the person row is named anonymous instead of absent.
• Nothing is read without the person's choice: the proposal is shown, never applied silently. identity --off still removes it.

Files: cli/src/contexts/telemetry/application/switch/, the identity and status use cases, presentation/display/telemetry*, the usage contract, the plugin README and the 00-init skill.

Content type

• Rule
• Skill
• Command
• Agent
• Plugin
• Other

Target tool(s)

• Claude Code
• Cursor
• Windsurf
• Gemini CLI
• Other

Additional context

Follows #993. The person axis only becomes useful once a team's figures are gathered (#662). This makes sure each person has chosen how they appear before that happens.

Code of Conduct

• I agree to follow this project's Code of Conduct.