refactor: simplify capability-based orchestration

[areshand]

Summary

• replace hard-coded task routing with a compact role capability catalog
• let the orchestrator choose the smallest role DAG from the goal and supervisor obligations
• make scouts optional while requiring independently reviewed supervisor approval before a no-scout implementation
• reduce the loaded orchestrator, routing, and lifecycle prompts by 575 lines to 220 total
• preserve detailed safety and repair regression contracts outside the loaded prompt
• add a mocked end-to-end test using real supervisor gates with deterministic agent responses

Mocked workflow coverage

• authority reviewer spawn and durable evidence sealing
• pre-implementation to implementation transition
• bounded worker spawn and assignment check
• post-implementation transition
• decision-drift and technical reviewer obligations
• supervisor completion transition
• exact four-agent graph with no unnecessary scout

Validation

• cargo test proposal_and_operation_roles_can_start_before_the_contract_gate
• bash tests/lifecycle.sh
• python3 -m unittest tests.test_swe_outcomes.NativeOutcomeTest.test_autonomous_authority_does_not_reopen_explicit_task_behavior
• tests/mock_orchestration_e2e.sh
• bash tests/run.sh