feat(diet): lagg till nordisk/carnivore/paleo + LCHF som matvanor med mjuk rankning

- DIET_PATTERNS: +nordic, +carnivore, +paleo (migration 0029). Ingen separat
  "lchf" - LCHF tacks av befintliga "low_carb" for att undvika dubblett med
  keto/low_carb. UI visar low_carb med etiketten "LCHF".
- Mobil onboarding + profil: 9 rena val (allatare..carnivore), 12 sprak.
- recommendation-engine: ny mjuk dietAffinity-poangterm (0-1, neutral 0.5).
  Rankar recept mot matvanan - ALDRIG hart filter (uteslutande matvanor,
  religion, allergener hanteras redan deterministiskt i sakerhetsfiltret).
  low_carb/keto: lag kolhydrat. carnivore: hog protein + lag kolhydrat.
  paleo: glutenfri/laktosfri-proxyer. nordic: svenskt/nordiskt kok + sasong.
- 6 nya tester (35 grona). Full typecheck 20/20 + mobil gron.

packages/recommendation-engine/src/scoring.ts

@@ -114,6 +114,10 @@ export function scoreCandidate(
     (candidate.mealTypes ?? []).includes("breakfast") || (candidate.mealTypes ?? []).includes("dessert");
   parts.mealFit = mainMeal && crossover ? 0.15 : 1;
 
+  // 17. Diet-affinitet (spec §diet): mjuk rankning mot matvanan. Aldrig ett hårt
+  // filter – uteslutande matvanor (vegan m.fl.) hanteras i säkerhetsfiltret.
+  parts.dietAffinity = dietAffinityFit(candidate, ctx);
+
   const score = weightedSum(parts, weights);
 
   return {
@@ -216,6 +220,64 @@ function cravingFit(candidate: RecommendationCandidate, ctx: RecommendationConte
   return checks === 0 ? 0.5 : hits / checks;
 }
 
+/**
+ * Mjuk diet-affinitet (spec §diet). Rankar recept som passar användarens matvana
+ * högre – men aldrig ett hårt filter: uteslutande matvanor (vegan/vegetarian/
+ * pescetarian), religion och allergener hanteras redan deterministiskt i
+ * säkerhetsfiltret före poängsättning. Returnerar 0–1 med 0.5 som neutralt
+ * utgångsläge när vi saknar signal (belägger aldrig ett straff vi inte kan visa –
+ * matchar den stödjande, icke-restriktiva hälsoprofilen, R7).
+ */
+function dietAffinityFit(candidate: RecommendationCandidate, ctx: RecommendationContext): number {
+  const diet = ctx.dietPattern;
+  if (!diet) return 0.5;
+  const { proteinG, carbsG } = candidate.nutritionPerPortion;
+  const tags = new Set<string>(candidate.tags);
+
+  switch (diet) {
+    case "low_carb":
+    case "keto": {
+      // LCHF/keto: låg kolhydrat premieras. Explicit low_carb-tagg = säkrast.
+      if (tags.has("low_carb")) return 1;
+      if (carbsG <= 15) return 1;
+      if (carbsG <= 30) return 0.75;
+      if (carbsG <= 50) return 0.45;
+      return 0.15;
+    }
+    case "carnivore": {
+      // Djurbaserat: hög proteinandel + mycket låg kolhydrat (macro-proxy). Vi
+      // saknar ingrediens-kategoriflaggor, så ingen hård uteslutning – salt och
+      // kryddor ska aldrig straffas.
+      const lowCarb = carbsG <= 10 ? 1 : carbsG <= 25 ? 0.5 : 0.15;
+      const highProtein = proteinG >= 35 ? 1 : proteinG >= 20 ? 0.6 : 0.3;
+      return clamp01(lowCarb * 0.6 + highProtein * 0.4);
+    }
+    case "paleo": {
+      // Paleo utesluter spannmål/baljväxter/mejeri/raffinerat socker. Exakta
+      // kategoriflaggor saknas -> tillförlitliga proxyer: glutenfri- och
+      // laktosfri-taggar är positiva signaler. Utan signal: neutral (0.5).
+      let score = 0.5;
+      if (tags.has("gluten_free")) score += 0.2;
+      if (tags.has("lactose_free")) score += 0.15;
+      if (tags.has("low_carb")) score += 0.1;
+      return clamp01(score);
+    }
+    case "nordic": {
+      // Nordisk: svenskt/nordiskt kök + säsong premieras.
+      const regional = candidate.cuisine === "swedish" || candidate.cuisine === "nordic";
+      const inSeason = candidate.peakSeasons.includes(ctx.currentSeason);
+      if (regional && inSeason) return 1;
+      if (regional) return 0.85;
+      if (inSeason) return 0.55;
+      return 0.4;
+    }
+    default:
+      // omnivore/flexitarian/mediterranean/high_protein + veg-mönster: neutral.
+      // (Veg-mönster hårdfiltreras redan; ingen rankningsskillnad behövs här.)
+      return 0.5;
+  }
+}
+
 interface FitResult {
   score: number;
   provenance: ProvenanceEntry[];

packages/recommendation-engine/src/types.ts

@@ -1,5 +1,6 @@
 import type {
   Cuisine,
+  DietPattern,
   MealType,
   MemoryItem,
   NutritionValues,
@@ -63,6 +64,12 @@ export interface RecommendationContext {
   isWeekday: boolean;
   isTrainingDay?: boolean | undefined;
   favoriteCuisines: Cuisine[];
+  /**
+   * Användarens matvana (spec §diet). Styr enbart MJUK rankning (dietAffinity) –
+   * hårda uteslutningar (vegan/vegetarian/pescetarian/religion/allergener) sker
+   * redan i säkerhetsfiltret före poängsättning. undefined = ingen preferens.
+   */
+  dietPattern?: DietPattern | undefined;
   /** Tolkade "jag är sugen på"-taggar (spec §19), redan normaliserade. */
   cravingTags?: string[] | undefined;
   cravingCuisine?: Cuisine | undefined;
@@ -106,6 +113,8 @@ export interface ScoringWeights {
   weather: number;
   craving: number;
   mealFit: number;
+  /** Mjuk diet-affinitet (spec §diet) – rankar recept som passar matvanan högre. */
+  dietAffinity: number;
   /** Nya S1-vikter; 0 om personalisering är av. */
   memoryFit: number;
   tasteFit: number;
@@ -126,6 +135,7 @@ export const DEFAULT_WEIGHTS: ScoringWeights = {
   weather: 3,
   craving: 15,
   mealFit: 12,
+  dietAffinity: 10,
   memoryFit: 6,
   tasteFit: 6,
   cookingAssumptionFit: 4,
@@ -159,6 +169,7 @@ export const TASTE_VIEW_WEIGHTS: ScoringWeights = {
   weather: 1,
   craving: 25,
   mealFit: 12,
+  dietAffinity: 8,
   memoryFit: 12,
   tasteFit: 12,
   cookingAssumptionFit: 6,
@@ -179,6 +190,7 @@ export const HEALTH_VIEW_WEIGHTS: ScoringWeights = {
   weather: 2,
   craving: 5,
   mealFit: 12,
+  dietAffinity: 14,
   memoryFit: 3,
   tasteFit: 3,
   cookingAssumptionFit: 4,
@@ -199,6 +211,7 @@ export const PANTRY_VIEW_WEIGHTS: ScoringWeights = {
   weather: 1,
   craving: 5,
   mealFit: 12,
+  dietAffinity: 8,
   memoryFit: 4,
   tasteFit: 4,
   cookingAssumptionFit: 8,

packages/recommendation-engine/test/engine.test.ts

@@ -486,3 +486,72 @@ describe("S4 rekommendationsvyer", () => {
     expect(tasteWeights.taste).toBe(TASTE_VIEW_WEIGHTS.taste);
   });
 });
+
+describe("diet-affinitet (spec §diet, mjuk rankning)", () => {
+  it("utan matvana är affiniteten neutral (0.5)", () => {
+    const scored = scoreCandidate(candidate(), ctx);
+    expect(scored.parts.dietAffinity).toBe(0.5);
+  });
+
+  it("low_carb/LCHF premierar låg kolhydrat", () => {
+    const low = scoreCandidate(candidate({ nutritionPerPortion: { ...nutrition, carbsG: 10 } }), {
+      ...ctx,
+      dietPattern: "low_carb",
+    });
+    const high = scoreCandidate(candidate({ nutritionPerPortion: { ...nutrition, carbsG: 60 } }), {
+      ...ctx,
+      dietPattern: "low_carb",
+    });
+    expect(low.parts.dietAffinity).toBe(1);
+    expect(high.parts.dietAffinity).toBe(0.15);
+  });
+
+  it("explicit low_carb-tagg räcker oavsett makro", () => {
+    const tagged = scoreCandidate(
+      candidate({ tags: ["low_carb"], nutritionPerPortion: { ...nutrition, carbsG: 55 } }),
+      { ...ctx, dietPattern: "keto" },
+    );
+    expect(tagged.parts.dietAffinity).toBe(1);
+  });
+
+  it("carnivore premierar högt protein + låg kolhydrat", () => {
+    const meaty = scoreCandidate(
+      candidate({ nutritionPerPortion: { ...nutrition, proteinG: 45, carbsG: 5 } }),
+      { ...ctx, dietPattern: "carnivore" },
+    );
+    const carby = scoreCandidate(
+      candidate({ nutritionPerPortion: { ...nutrition, proteinG: 12, carbsG: 70 } }),
+      { ...ctx, dietPattern: "carnivore" },
+    );
+    expect(meaty.parts.dietAffinity).toBe(1);
+    expect(meaty.parts.dietAffinity).toBeGreaterThan(carby.parts.dietAffinity ?? 0);
+  });
+
+  it("nordisk premierar svenskt/nordiskt kök", () => {
+    const swedish = scoreCandidate(candidate({ cuisine: "swedish" }), {
+      ...ctx,
+      dietPattern: "nordic",
+    });
+    const italian = scoreCandidate(candidate({ cuisine: "italian" }), {
+      ...ctx,
+      dietPattern: "nordic",
+    });
+    expect(swedish.parts.dietAffinity).toBe(0.85);
+    expect(swedish.parts.dietAffinity).toBeGreaterThan(italian.parts.dietAffinity ?? 0);
+  });
+
+  it("är mjuk rankning, inte hårt filter – ej matchande recept finns kvar", () => {
+    const lowCarbRecipe = candidate({
+      recipeId: "lowcarb",
+      nutritionPerPortion: { ...nutrition, carbsG: 8 },
+    });
+    const pastaRecipe = candidate({
+      recipeId: "pasta",
+      nutritionPerPortion: { ...nutrition, carbsG: 80 },
+    });
+    const ranked = rankAll([pastaRecipe, lowCarbRecipe], { ...ctx, dietPattern: "low_carb" });
+    // Båda recepten finns kvar (inget filtreras bort), men lågkolhydrat rankas högre.
+    expect(ranked).toHaveLength(2);
+    expect(ranked[0]?.recipeId).toBe("lowcarb");
+  });
+});

packages/shared-types/src/enums.ts

@@ -140,6 +140,13 @@ export const DIET_PATTERNS = [
   "keto",
   "high_protein",
   "mediterranean",
+  // Tillagda (spec §diet): nordiskt, carnivore, paleo. Additivt – gamla värden
+  // orörda, ingen dataförlust. Rankas/AI-styrs snarare än hårdfiltreras.
+  // OBS: ingen separat "lchf" – LCHF täcks av befintliga "low_carb" (undviker
+  // dubblett med keto/low_carb). UI visar "low_carb" med etiketten "LCHF".
+  "nordic",
+  "carnivore",
+  "paleo",
 ] as const;
 export type DietPattern = (typeof DIET_PATTERNS)[number];