fix: weekly meal-plan nutrition compared a week's total against a daily goal

userNutritionGoals are daily targets (the nutrition diary already compares
a single day's totals against them directly) — but the weekly meal-plan
route summed an entire week's entries and compared that raw total straight
against the same daily number, so coverage read roughly 7x too high.

Now computes a daily average (across days that actually have planned
meals) and compares that against the goal instead, adds a per-day
breakdown (byDay) for a future day-view, and tracks unknownCount for
entries whose recipe has no nutrition data yet, matching the diary route.

Also fixed a real bug this surfaced: meal-plan/page.tsx and print/meal-plan
parsed the ?week= date via new Date(dateStr) (UTC midnight) then read
.getDay() (local time) — in positive-UTC-offset timezones this resolves to
the wrong Monday, and the reverse (Date -> string via toISOString()) has
the same mismatch in the other direction. Both now do local y/m/d math
throughout.

Verified locally: correct daily-average math end to end (recipe entry +
batch-dish entry, which already attributed nutrition correctly via its
required parent recipeId — no separate fix needed there), and confirmed
the meal-plan page now resolves the right week and renders real coverage
bars against actual planned entries.

apps/web/components/nutrition/weekly-nutrition-bar.tsx

@@ -25,6 +25,8 @@ type NutritionCoverage = {
 
 type NutritionResponse = {
   totals: NutritionTotals;
+  dailyAverage: NutritionTotals;
+  unknownCount: number;
   goals: NutritionGoals;
   coverage: NutritionCoverage;
 };
@@ -54,12 +56,12 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
 
   if (!data || !data.goals) return null;
 
-  const { totals, goals, coverage } = data;
+  const { dailyAverage, goals, coverage, unknownCount } = data;
 
   const bars: BarItem[] = [
     {
       label: "Calories",
-      value: totals.calories,
+      value: dailyAverage.calories,
       goal: goals.caloriesKcal,
       unit: "kcal",
       percentage: coverage.calories,
@@ -67,7 +69,7 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
     },
     {
       label: "Protein",
-      value: totals.protein,
+      value: dailyAverage.protein,
       goal: goals.proteinG,
       unit: "g",
       percentage: coverage.protein,
@@ -75,7 +77,7 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
     },
     {
       label: "Carbs",
-      value: totals.carbs,
+      value: dailyAverage.carbs,
       goal: goals.carbsG,
       unit: "g",
       percentage: coverage.carbs,
@@ -83,7 +85,7 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
     },
     {
       label: "Fat",
-      value: totals.fat,
+      value: dailyAverage.fat,
       goal: goals.fatG,
       unit: "g",
       percentage: coverage.fat,
@@ -93,6 +95,7 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
 
   return (
     <div className="space-y-3">
+      <p className="text-xs text-muted-foreground">Daily average vs. your goals</p>
       {bars.map((bar) => {
         if (bar.goal == null) return null;
         const width = Math.min(bar.percentage, 100);
@@ -113,6 +116,11 @@ export function WeeklyNutritionBar({ weekStart }: WeeklyNutritionBarProps) {
           </div>
         );
       })}
+      {unknownCount > 0 && (
+        <p className="text-xs text-muted-foreground">
+          {unknownCount} planned {unknownCount === 1 ? "meal" : "meals"} missing nutrition data — estimate it from the recipe page for a more accurate picture.
+        </p>
+      )}
     </div>
   );
 }