[Foundation] Verify orchestrator delegation and model-effort routing

[pate0304]

Outcome

Provide reproducible fresh-session proof that the project Codesemble Orchestrator can coordinate bounded specialist work while the primary thread retains final authority.

Acceptance criteria

• Orchestrator discovery and nested delegation are captured against the exact plugin/team payload.
• Primary authority and prohibited external actions are enforced and documented.
• Configured agent model and reasoning effort are compared with actual child runtime context.
• The observed reasoning-effort fallback is diagnosed and covered by regression tests.
• Ephemeral-session and result-collection limitations are surfaced honestly.