feat(mcp): gnubok_reconcile_residual stages residual booking + link on a bank account (#1872)

The residual door existed for the page and the v1 API (#1862) but not for
agents: an MCP client that found a 10 kr bank fee between a selection and its
verifikat had to hand the last step back to the user. gnubok_reconcile_residual
dry-runs lib/reconciliation/residual.ts at stage time (so zero / cap /
direction / skattekonto refusals surface immediately), stages a
reconciliation_residual operation with the would-book verifikat as the
preview, and commitReconciliationResidual links and books on approval.

Risk 'medium' (one typed verifikat bounded by RESIDUAL_MAX_AMOUNT, undone by
storno + unmatch); scope transactions:write like the v1 route. The op type
is added to the pending_operations CHECK (NOT VALID + VALIDATE pair, list
verified against the live prod constraint 2026-08-25), and the tool joins
the reconcile_month / close_period loadouts and the reconcile-month skill.

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

extensions/general/mcp-server/recommended-tools.ts

@@ -68,6 +68,7 @@ export const RECOMMENDED_WORKFLOW_LOADOUTS: readonly WorkflowLoadout[] = [
       // staged link (bank accounts and skattekonto alike).
       'gnubok_list_reconciliation_items',
       'gnubok_reconcile_match',
+      'gnubok_reconcile_residual',
       'gnubok_reconcile_signoff',
       'gnubok_list_voucher_gaps',
       'gnubok_explain_voucher_gap',
@@ -84,6 +85,9 @@ export const RECOMMENDED_WORKFLOW_LOADOUTS: readonly WorkflowLoadout[] = [
       'gnubok_list_reconciliation_items',
       'gnubok_reconcile_match',
       'gnubok_reconcile_unmatch',
+      // Near-miss on a bank account (fee, interest, rounding): link and book
+      // the difference in one staged step.
+      'gnubok_reconcile_residual',
       // Rows with no counterpart: book them (bank side) or link to the
       // verifikat that already holds the affärshändelse.
       'gnubok_categorize_transaction',