feat: align evidence review pack product process flow (Spec 337) (#407)
## Summary
Productizes the Evidence Overview review-pack process flow so the operator sees a clear, gated progression:
`evidence snapshot → stored report → review pack → customer-safe export`
with explicit gating, state-appropriate copy, collapsed diagnostics, and dark-mode coverage.
## Changes
- `EvidenceOverview` page + Blade view aligned to the review-pack state contract.
- New feature test: `Spec337EvidenceReviewPackProductFlowTest`.
- New browser smoke: `Spec337EvidenceReviewPackProductFlowSmokeTest`.
- Spec 337 artifacts: `spec.md`, `plan.md`, `tasks.md`, state contract, repo-truth map, checklist, and screenshot evidence.
## Spec Kit
Spec + code in one PR (Variante B). Gate satisfied: includes `specs/337-evidence-review-pack-product-process-flow-alignment/`.
## Notes
Filament v5 / Livewire v4 compliant. No destructive actions added. Tooling scratch (`.playwright-mcp/`) intentionally excluded from the commit.
Co-authored-by: Ahmed Darrazi <ahmed.darrazi@live.de>
Reviewed-on: #407