feat: show actual transactions in budget previous year column

Replace planned budget data with actual transaction totals for the
previous year column in the budget table. Add getActualTotalsForYear
helper to budgetService.

Ref #34

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.fr.md

@@ -2,6 +2,9 @@
 
 ## [Non publié]
 
+### Modifié
+- Tableau de budget : la colonne année précédente affiche maintenant le réel (transactions) au lieu du budget planifié (#34)
+
 ## [0.6.5]
 
 ### Ajouté

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+### Changed
+- Budget table: previous year column now shows actual transactions instead of planned budget (#34)
+
 ## [0.6.5]
 
 ### Added

src/hooks/useBudget.ts

@@ -3,6 +3,7 @@ import type { BudgetYearRow, BudgetTemplate } from "../shared/types";
 import {
   getAllActiveCategories,
   getBudgetEntriesForYear,
+  getActualTotalsForYear,
   upsertBudgetEntry,
   upsertBudgetEntriesForYear,
   getAllTemplates,
@@ -72,10 +73,10 @@ export function useBudget() {
     dispatch({ type: "SET_ERROR", payload: null });
 
     try {
-      const [allCategories, entries, prevYearEntries, templates] = await Promise.all([
+      const [allCategories, entries, prevYearActuals, templates] = await Promise.all([
         getAllActiveCategories(),
         getBudgetEntriesForYear(year),
-        getBudgetEntriesForYear(year - 1),
+        getActualTotalsForYear(year - 1),
         getAllTemplates(),
       ]);
 
@@ -88,10 +89,10 @@ export function useBudget() {
         entryMap.get(e.category_id)!.set(e.month, e.amount);
       }
 
-      // Build a map for previous year totals: categoryId -> annual total
+      // Build a map for previous year actuals: categoryId -> annual actual total
       const prevYearTotalMap = new Map<number, number>();
-      for (const e of prevYearEntries) {
+      for (const a of prevYearActuals) {
-        prevYearTotalMap.set(e.category_id, (prevYearTotalMap.get(e.category_id) ?? 0) + e.amount);
+        if (a.category_id != null) prevYearTotalMap.set(a.category_id, a.actual);
       }
 
       // Helper: build months array from entryMap

src/services/budgetService.ts

@@ -178,6 +178,16 @@ export async function deleteTemplate(templateId: number): Promise<void> {
   await db.execute("DELETE FROM budget_templates WHERE id = $1", [templateId]);
 }
 
+// --- Actuals helpers ---
+
+export async function getActualTotalsForYear(
+  year: number
+): Promise<Array<{ category_id: number | null; actual: number }>> {
+  const dateFrom = `${year}-01-01`;
+  const dateTo = `${year}-12-31`;
+  return getActualsByCategoryRange(dateFrom, dateTo);
+}
+
 // --- Budget vs Actual ---
 
 async function getActualsByCategoryRange(

src/shared/types/index.ts

@@ -142,7 +142,7 @@ export interface BudgetYearRow {
   depth?: number;
   months: number[]; // index 0-11 = Jan-Dec planned amounts
   annual: number;   // computed sum
-  previousYearTotal: number; // total budget from the previous year
+  previousYearTotal: number; // actual (transactions) total from the previous year
 }
 
 export interface ImportConfigTemplate {