feat(fusion_accounting_reports): Phase 2 skeleton + plan

46-task plan to replace Enterprise account_reports module:
- CORE scope: P&L, balance sheet, trial balance, GL with drill-down
- HYBRID engine: shared primitives + per-report models
- AI augmentation: anomaly detection + LLM-generated commentary
- Coexists with Enterprise (group_fusion_show_when_enterprise_absent)
- Same V19 conventions + test pyramid + perf-budget discipline as Phase 1

Skeleton: empty manifest + dirs + icon. Tasks 3-46 add the substance.
Made-with: Cursor

fusion_accounting_reports/security/ir.model.access.csv

@@ -0,0 +1 @@
+id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink