Support up to 3 levels of categories (e.g., Dépenses récurrentes →
Assurances → Assurance-auto) while keeping SQL JOINs bounded and
existing 2-level branches fully compatible.
Changes across 14 files:
- Types: add "level3" pivot field, depth property on budget row types
- Reports: grandparent JOIN for 3-level resolution in dynamic reports
- Categories: depth validation (max 3), auto is_inputable management,
recursive tree operations, 3-level drag-drop with subtree validation
- Budget: 3-level grouping with intermediate subtotals, leaf-only
aggregation, depth-based indentation (pl-8/pl-14)
- Seed data: Assurances split into Assurance-auto/habitation/vie
- i18n: level3 translations for FR and EN
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>