feat: per-tier feature toggles for recipe variations/pairings (v0.50.0)

Admins can now disable specific AI features per tier from Admin > Tier
Limits — new feature_flags table (feature x tier -> enabled, defaulting
to true so adding a new gated feature never needs a backfill).

Covers recipe variations, drink pairing, and meal pairing to start.
When disabled for a user's tier, the button stays visible (with a small
lock badge) but opens an upgrade dialog instead of running; the API
route rejects the call server-side either way (requireFeatureEnabled,
re-reads tier from the DB rather than trusting the session's cache,
same rationale as checkAndIncrementTierLimit).

The upgrade dialog is informational only — no Stripe checkout exists
yet (STRIPE_PLAN.md is still just a plan) — its CTA links to /support
prefilled as an upgrade-interest suggestion.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/(app)/recipes/[id]/page.tsx

@@ -41,6 +41,7 @@ import { KeepScreenAwake } from "@/components/recipe/keep-screen-awake";
 import { ExportMarkdownButton } from "@/components/shared/export-markdown-button";
 import { recipeToMarkdown } from "@/lib/markdown/recipe";
 import { getMessages, formatMessage } from "@/lib/i18n/server";
+import { getFeatureFlagMatrix, type Tier } from "@/lib/feature-flags";
 
 type Params = { params: Promise<{ id: string }> };
 
@@ -70,7 +71,7 @@ export default async function RecipePage({ params }: Params) {
   const DIETARY_LABELS = m.recipe.dietary;
   const unitPref = (session.user as { unitPref?: string }).unitPref === "imperial" ? "imperial" : "metric";
 
-  const [recipe, ratingData, favoriteData, myRating, forkedFrom, myNote, dishCookLog] = await Promise.all([
+  const [recipe, ratingData, favoriteData, myRating, forkedFrom, myNote, dishCookLog, featureFlags] = await Promise.all([
     db.query.recipes.findFirst({
       where: and(
         eq(recipes.id, id),
@@ -100,10 +101,18 @@ export default async function RecipePage({ params }: Params) {
       orderBy: desc(cookingHistory.cookedAt),
       columns: { batchDishId: true, cookedAt: true },
     }),
+    getFeatureFlagMatrix(),
   ]);
 
   if (!recipe) notFound();
 
+  const viewerTier = (session.user as { tier?: string }).tier as Tier | undefined ?? "free";
+  const locked = {
+    variations: !featureFlags.recipe_variations[viewerTier],
+    drinkPairing: !featureFlags.drink_pairing[viewerTier],
+    mealPairing: !featureFlags.meal_pairing[viewerTier],
+  };
+
   const isOwner = recipe.authorId === session.user.id;
 
   const dishCookedAtMap = new Map<string, string>();
@@ -176,8 +185,8 @@ export default async function RecipePage({ params }: Params) {
             <FavoriteButton recipeId={id} initialFavorited={isFavorited} />
             {!recipe.isBatchCook && recipe.recipeType !== "drink" && (
               <>
-                <MealPairingButton recipeId={id} />
-                <DrinkPairingButton recipeId={id} />
+                <MealPairingButton recipeId={id} locked={locked.mealPairing} />
+                <DrinkPairingButton recipeId={id} locked={locked.drinkPairing} />
               </>
             )}
             {recipe.visibility === "public" && (
@@ -229,6 +238,7 @@ export default async function RecipePage({ params }: Params) {
                 timerSeconds: s.timerSeconds,
                 order: s.order,
               }))}
+              locked={locked.variations}
             />
             <ForkRecipeButton recipeId={id} variant={isOwner ? "duplicate" : "fork"} />
             <ShareRecipeButton recipeId={id} visibility={recipe.visibility} />

apps/web/app/(app)/support/page.tsx

@@ -5,14 +5,25 @@ import { db, supportTickets, eq, desc } from "@epicure/db";
 import { SupportManager } from "@/components/support/support-manager";
 import { getMessages } from "@/lib/i18n/server";
 import { getPublicUrl } from "@/lib/storage";
+import { FEATURE_DEFINITIONS } from "@/lib/feature-flags";
 
 export const metadata: Metadata = {};
 
-export default async function SupportPage() {
+export default async function SupportPage({
+  searchParams,
+}: {
+  searchParams: Promise<{ upgrade?: string }>;
+}) {
   const session = await auth.api.getSession({ headers: await headers() });
   if (!session) return null;
   const m = getMessages((session.user as { locale?: string }).locale);
 
+  const { upgrade } = await searchParams;
+  const upgradeFeature = FEATURE_DEFINITIONS.find((f) => f.key === upgrade);
+  const prefill = upgradeFeature
+    ? { type: "suggestion" as const, title: `Interested in upgrading for: ${upgradeFeature.label}` }
+    : undefined;
+
   const rows = await db.query.supportTickets.findMany({
     where: eq(supportTickets.userId, session.user.id),
     orderBy: desc(supportTickets.createdAt),
@@ -26,6 +37,7 @@ export default async function SupportPage() {
         <p className="text-muted-foreground text-sm mt-1">{m.support.subtitle}</p>
       </div>
       <SupportManager
+        prefill={prefill}
         initialTickets={rows.map((r) => ({
           id: r.id,
           type: r.type,