fix(bench): reflect Odinn one-shot capabilities

[jason-allen-oneal]

What changed

• remove the unsupported process.exec capability and nonexistent process flags from the maintained Odinn one-shot adapters
• narrow the prepared Odinn benchmark identity to governed workspace reads and mutations
• report process-dependent cases as unsupported without weakening the product policy
• add regression coverage for both maintained adapter fixtures

Why

Odinn Forge v1.1.1 permits process.exec only as a separately approved top-level durable job. The one-shot agent.run adapter cannot compose that surface, so advertising it converted three unsupported cases into fifteen false failures.

Validation

• pnpm check
• 27 tests passed
• git diff --check