team: bilingual EN/FR report

[pierrick-fonquerne]

Scope

• The synthesis and verification steps now produce every human-readable string in English and French (no extra API calls). French fields are optional with serde defaults, so a model that returns English only still deserializes and renders.
• The PR comment shows a shared header (verdict and counts), then an English block and a French block (open by default) as collapsible sections.
• Confirmed minor findings are collapsed under a nested section to keep the comment short. Inline comments show French first, English second.

Acceptance criteria

• The comment contains both an English and a French collapsible block (French open by default).
• Missing French fields fall back to English (tolerant deserialization).
• Minor confirmed findings are collapsed; criticals stay visible.
• fmt + clippy (all/pedantic, -D warnings) + tests are green (36 tests).