Deepen Account + Stock modules significantly

Account (+400 LOC):
- Accounting reports: Trial Balance, Balance Sheet, Profit & Loss,
  Aged Receivable/Payable, General Ledger (SQL-based generation)
- account.report + account.report.line models
- Analytic accounting: account.analytic.plan, account.analytic.account,
  account.analytic.line models
- Bank statement matching (button_match with 1% tolerance)
- 6 default report definitions seeded
- 8 new actions + 12 new menus (Vendor Bills, Payments, Bank Statements,
  Reporting, Configuration with Chart of Accounts/Journals/Taxes)

Stock (+230 LOC):
- Stock valuation: price_unit + value (computed) on moves and quants
- Reorder rules: stock.warehouse.orderpoint with min/max qty,
  qty_on_hand compute from quants, action_replenish method
- Scrap: stock.scrap model with action_validate (quant transfer)
- Inventory adjustment: stock.quant.adjust wizard (set qty directly)
- Scrap location seeded

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

addons/account/models/init.go

@@ -12,4 +12,7 @@ func Init() {
 	initAccountReconcile()
 	initAccountBankStatement()
 	initAccountFiscalPosition()
+	initAccountTaxReport()
+	initAccountReportLine()
+	initAccountAnalytic()
 }