Adds three new method families on ReportsAdapter that route through
fusion.report.engine when fusion_accounting_reports is installed:
- run_fusion_report (pnl/balance_sheet/trial_balance/general_ledger)
- get_anomalies (variance detection on engine output)
- get_commentary (LLM narrative; falls back to templated)
These coexist with the legacy ref_id-shaped run_report / export_report
API so existing reporting tools (profit_loss, balance_sheet, etc.) keep
working unchanged. FUSION_MODEL is updated to fusion.report.engine so
mode detection picks FUSION when the new engine is installed.
4 new TransactionCase tests cover the fusion + community paths.
Made-with: Cursor
15cf4e129f