feat(decision-council): verify execution preflight before dispatch

[9uiLe]

Summary

• add a host-neutral execution preflight contract and deterministic guard
• distinguish requested/effective model and effort with runtime/probe provenance
• block known mismatch, silent fallback, unsafe context, and unbounded limits before dispatch
• require finite token ceilings and owner-backed authorization for budget excess
• support explicitly degraded low-stakes operation and post-run usage variance reporting

Decision Council dogfood

• froze O1 model/effort mismatch detection, O2 usage/loop bounds, and O3 host-neutral degradation
• verified the requested Fable 5 and Codex gpt-5.6-sol/high terminal configurations before dispatch
• incorporated Fable challenge concerns about config-sourced verification, missing ceilings, weak authorization provenance, and expected-vs-maximum variance
• filed [Orchestration] Dispatch can complete without durable worker_done or recoverable result #57 after an Orca Fable dispatch completed without a durable worker_done or recoverable response

Testing

• node --test plugins/second-opinion/tests/*.test.mjs
• python ~/.codex/skills/.system/skill-creator/scripts/quick_validate.py plugins/second-opinion/skills/decision-council
• ./scripts/verify-versions.sh
• git diff --check

Closes #54