feat(receipt-import): expand deterministic category rules and AI contradiction guards

NEXT_STEPS.md

@@ -88,6 +88,10 @@
 5. Lokalisera `receipt_import_tab.dart` och `swipeable_inventory_tile.dart`.
 6. Smoke-test på testdomän och avstämning.
 7. Planera och påbörja avancerad AI-integration och EAN-skanning.
+8. AI-kategorisering: kandidatbegränsning före AI (narrowing till relevant gren/kandidatlista istället för hela kategoriträdet).
+9. AI-kategorisering: egen confidence-score i backend (regel/lexikal signal + AI-signal), inte enbart modellens confidence.
+10. AI-kategorisering: logga användarkorrigeringar och bygg feedbackloop för nya regler/synonymer.
+11. AI-kategorisering: utvärdera alternativ modell för kategorisering med A/B-test på historiska kvittorader.
 
 ## Beslut 2026-05-02 - Aliasstrategi för kvittoimport
 

backend/src/receipt-import/receipt-import.service.ts

@@ -261,7 +261,12 @@ export class ReceiptImportService {
         }
 
         const suggestion = await this.aiService.suggestCategory(item.rawName, categories);
-        enriched.set(item.rawName, { ...item, categorySuggestion: suggestion });
+        const guardedSuggestion = this.applyContradictionGuard(
+          item.rawName,
+          suggestion,
+          categories,
+        );
+        enriched.set(item.rawName, { ...item, categorySuggestion: guardedSuggestion });
       } catch {
         // Om AI-anrop misslyckas för enskild vara — hoppa över utan att kasta
         enriched.set(item.rawName, item);
@@ -276,6 +281,188 @@ export class ReceiptImportService {
     categories: Awaited<ReturnType<CategoriesService['findFlattened']>>,
   ): CategorySuggestion | null {
     const normalized = normalizeForRules(rawName);
+    const findCategory = (opts: {
+      name: string;
+      startsWith?: string;
+      includes?: string;
+    }) =>
+      categories.find((c) => {
+        const cName = c.name.toLowerCase();
+        const cPath = c.path.toLowerCase();
+        if (cName !== opts.name.toLowerCase()) return false;
+        if (opts.startsWith && !cPath.startsWith(opts.startsWith.toLowerCase())) return false;
+        if (opts.includes && !cPath.includes(opts.includes.toLowerCase())) return false;
+        return true;
+      });
+
+    const toSuggestion = (
+      cat: { id: number; name: string; path: string } | undefined,
+      confidence: 'high' | 'medium' = 'high',
+    ): CategorySuggestion | null => {
+      if (!cat) return null;
+      return {
+        categoryId: cat.id,
+        categoryName: cat.name,
+        path: cat.path,
+        confidence,
+        usedFallback: false,
+      };
+    };
+
+    // ── Regel: Kött/chark (bacon/fläsk m.m.) ────────────────────────────
+    const hasPorkSignal =
+      /\bbacon\b/.test(normalized) ||
+      /\bsidflask\b/.test(normalized) ||
+      /\bpancetta\b/.test(normalized) ||
+      /\bflask\b/.test(normalized) ||
+      /\bflaskfile\b/.test(normalized) ||
+      /\bkarr[eé]\b/.test(normalized) ||
+      /\bkotlett\b/.test(normalized);
+
+    if (hasPorkSignal) {
+      const l3Pork = findCategory({
+        name: 'fläsk',
+        startsWith: 'kött, chark & fågel > kött > ',
+      });
+      const hit = toSuggestion(l3Pork, 'high');
+      if (hit) return hit;
+    }
+
+    // ── Regel: Korvfamiljen ─────────────────────────────────────────────
+    const hasSausageSignal =
+      /\bkorv\b/.test(normalized) ||
+      /\bfalukorv\b/.test(normalized) ||
+      /\bchorizo\b/.test(normalized) ||
+      /\bbratwurst\b/.test(normalized) ||
+      /\bwienerkorv\b/.test(normalized) ||
+      /\bgrillkorv\b/.test(normalized) ||
+      /\bprinskorv\b/.test(normalized) ||
+      /\bolkorv\b/.test(normalized);
+
+    if (hasSausageSignal) {
+      const isVegetarian =
+        /\bvegetarisk\b/.test(normalized) ||
+        /\bvegansk\b/.test(normalized) ||
+        /\bvego\b/.test(normalized);
+      if (isVegetarian) {
+        const vegSausage = findCategory({
+          name: 'vegetarisk korv',
+          startsWith: 'kött, chark & fågel > korv > ',
+        });
+        const hit = toSuggestion(vegSausage, 'high');
+        if (hit) return hit;
+      }
+
+      if (/\bolkorv\b/.test(normalized)) {
+        const beerSausage = findCategory({
+          name: 'ölkorv',
+          startsWith: 'kött, chark & fågel > korv > ',
+        });
+        const hit = toSuggestion(beerSausage, 'high');
+        if (hit) return hit;
+      }
+
+      const sausageGeneral = findCategory({
+        name: 'grill, kok- & kryddkorv',
+        startsWith: 'kött, chark & fågel > korv > ',
+      });
+      const hit = toSuggestion(sausageGeneral, 'high');
+      if (hit) return hit;
+    }
+
+    // ── Regel: Fågel (färsk/fryst) ──────────────────────────────────────
+    const hasPoultrySignal =
+      /\bkyckling\b/.test(normalized) ||
+      /\bkalkon\b/.test(normalized) ||
+      /\bdrumsticks?\b/.test(normalized) ||
+      /\bling?file\b/.test(normalized) ||
+      /\blarfile\b/.test(normalized) ||
+      /\bkycklinglar\b/.test(normalized);
+
+    if (hasPoultrySignal) {
+      const isFrozen = /\bfryst\b/.test(normalized) || /\bdjupfryst\b/.test(normalized);
+      if (isFrozen) {
+        const frozenPoultry = findCategory({
+          name: 'fryst fågel',
+          startsWith: 'kött, chark & fågel > fågel > ',
+        });
+        const hit = toSuggestion(frozenPoultry, 'high');
+        if (hit) return hit;
+      }
+
+      const freshPoultry = findCategory({
+        name: 'färsk fågel',
+        startsWith: 'kött, chark & fågel > fågel > ',
+      });
+      const hit = toSuggestion(freshPoultry, 'high');
+      if (hit) return hit;
+    }
+
+    // ── Regel: Pålägg (korv/salami vs skivat) ───────────────────────────
+    const hasColdCutSignal =
+      /\bpalagg\b/.test(normalized) ||
+      /\bpalegg\b/.test(normalized) ||
+      /\bskivad\b/.test(normalized) ||
+      /\bsalami\b/.test(normalized) ||
+      /\bmedvurst\b/.test(normalized) ||
+      /\bpastrami\b/.test(normalized) ||
+      /\bskinka\b/.test(normalized);
+
+    if (hasColdCutSignal) {
+      const hasSlicedSausageSignal =
+        /\bsalami\b/.test(normalized) ||
+        /\bmedvurst\b/.test(normalized) ||
+        /\bpastrami\b/.test(normalized);
+      if (hasSlicedSausageSignal) {
+        const salamiColdCut = findCategory({
+          name: 'korv & salami',
+          startsWith: 'kött, chark & fågel > pålägg > ',
+        });
+        const hit = toSuggestion(salamiColdCut, 'high');
+        if (hit) return hit;
+      }
+
+      const slicedColdCut = findCategory({
+        name: 'skivat pålägg',
+        startsWith: 'kött, chark & fågel > pålägg > ',
+      });
+      const hit = toSuggestion(slicedColdCut, 'high');
+      if (hit) return hit;
+    }
+
+    // ── Regel: Färs ──────────────────────────────────────────────────────
+    const hasMinceSignal =
+      /\bfars\b/.test(normalized) ||
+      /\bfarse\b/.test(normalized) ||
+      /\bmince\b/.test(normalized) ||
+      /\bköttfärs\b/.test(rawName.toLowerCase());
+
+    if (hasMinceSignal && !hasPoultrySignal) {
+      const mince = findCategory({
+        name: 'köttfärs',
+        startsWith: 'kött, chark & fågel > kött > ',
+      });
+      const hit = toSuggestion(mince, 'high');
+      if (hit) return hit;
+    }
+
+    // ── Regel: Nöt/kalv (hela detaljer) ─────────────────────────────────
+    const hasBeefVealSignal =
+      /\bnot\b/.test(normalized) ||
+      /\bkalv\b/.test(normalized) ||
+      /\bbiff\b/.test(normalized) ||
+      /\bentrecote\b/.test(normalized) ||
+      /\brostbiff\b/.test(normalized) ||
+      /\bryggbiff\b/.test(normalized);
+
+    if (hasBeefVealSignal && !hasMinceSignal) {
+      const beefVeal = findCategory({
+        name: 'nöt & kalv',
+        startsWith: 'kött, chark & fågel > kött > ',
+      });
+      const hit = toSuggestion(beefVeal, 'high');
+      if (hit) return hit;
+    }
 
     // ── Regel: Te ────────────────────────────────────────────────────────
     const isTea =
@@ -380,4 +567,46 @@ export class ReceiptImportService {
 
     return null;
   }
+
+  private applyContradictionGuard(
+    rawName: string,
+    suggestion: CategorySuggestion,
+    categories: Awaited<ReturnType<CategoriesService['findFlattened']>>,
+  ): CategorySuggestion {
+    const normalized = normalizeForRules(rawName);
+    const hasPorkSignal =
+      /\bbacon\b/.test(normalized) ||
+      /\bsidflask\b/.test(normalized) ||
+      /\bpancetta\b/.test(normalized) ||
+      /\bflask\b/.test(normalized) ||
+      /\bflaskfile\b/.test(normalized) ||
+      /\bkarr[eé]\b/.test(normalized) ||
+      /\bkotlett\b/.test(normalized);
+
+    if (!hasPorkSignal) return suggestion;
+
+    const aiPath = suggestion.path.toLowerCase();
+    const isClearlyWrongBranch =
+      aiPath.includes('köttbullar & färsprodukter') || aiPath.includes('köttfärs');
+
+    if (!isClearlyWrongBranch) return suggestion;
+
+    const l3Pork = categories.find(
+      (c) =>
+        c.name.toLowerCase() === 'fläsk' &&
+        c.path.toLowerCase().startsWith('kött, chark & fågel > kött > '),
+    );
+    if (!l3Pork) return suggestion;
+
+    this.logger.log(
+      `AI contradiction-guard: "${rawName}" remappas från "${suggestion.path}" till "${l3Pork.path}"`,
+    );
+    return {
+      categoryId: l3Pork.id,
+      categoryName: l3Pork.name,
+      path: l3Pork.path,
+      confidence: 'high',
+      usedFallback: true,
+    };
+  }
 }