Fix reviewer verdict modes

[aermin]

Summary

• make the existing Sol / High reviewer explicitly support commitment and final modes with non-overlapping verdict vocabularies
• add top-level mode controls to both role packets and fail closed on missing, duplicate, contradictory, or invalid controls while treating mode-like evidence as inert
• migrate only the byte-exact v0.4.0 reviewer and refuse modified, unknown, symlinked, or nonregular reviewer files before any companion-file mutation
• add verifier coverage for packet structure, vocabulary separation, the control/evidence boundary, exact migration, and zero-partial-mutation refusals

Validation

• sh plugins/sol-advisor/scripts/verify.sh — passes in a disposable checkout with the independent one-line manifest prerequisite from Fix verifier manifest assertion and add CI #9 applied; current main otherwise stops at that pre-existing manifest assertion before reaching these tests
• uv run --no-project --with pyyaml python .../skill-creator/scripts/quick_validate.py plugins/sol-advisor/skills/orchestration — Skill is valid!
• uv run --no-project --with pyyaml python .../plugin-creator/scripts/validate_plugin.py plugins/sol-advisor — passed
• git diff --check — passed

Fixes #5