fix(home): 'use template' card opens template detail page (was → /templates)

Homepage TemplateGallery card called the old Supabase createVideoProject which
failed → fell back to /templates. Now it routes to /templates/{slug} (detail),
where the user picks aspect/style and starts the project. Removed dead handler/imports.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/sections/TemplateGallery.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useCallback, useState } from "react";
+import { useState } from "react";
 import { useRouter } from "next/navigation";
 import Link from "next/link";
 import { AnimatePresence, motion } from "framer-motion";
@@ -8,7 +8,6 @@ import { ArrowRight } from "lucide-react";
 import { useTranslations } from "next-intl";
 
 import { cn } from "@/lib/utils";
-import { createVideoProject } from "@/lib/create-video-project";
 import type { AdminProject } from "@/lib/admin-api";
 
 import { SectionReveal } from "./SectionReveal";
@@ -58,7 +57,6 @@ export function TemplateGallery({ className, adminItems }: TemplateGalleryProps)
   const router = useRouter();
   const t = useTranslations("templates");
   const [activeTab, setActiveTab] = useState<FilterTab>("All");
-  const [usingTemplateId, setUsingTemplateId] = useState<string | null>(null);
 
   // Real admin templates only — no hardcoded demo fallback.
   const allItems: TemplateItem[] = (adminItems ?? []).map(adminProjectToTemplateItem);
@@ -74,38 +72,11 @@ export function TemplateGallery({ className, adminItems }: TemplateGalleryProps)
     Business: t("tabBusiness"),
   };
 
-  const handleUseTemplate = useCallback(
-    async (template: TemplateItem) => {
-      if (usingTemplateId) return;
-      setUsingTemplateId(template.id);
-
-      // Image templates → create an image project (future)
-      // All others → video project
-      const isImage = template.category === "Images";
-      if (isImage) {
-        router.push("/dashboard");
-        setUsingTemplateId(null);
-        return;
-      }
-
-      const result = await createVideoProject({ name: template.name });
-      setUsingTemplateId(null);
-
-      if (!result.ok) {
-        // Dev mode: Supabase not configured → go to new-project onboarding
-        if (result.error.includes("Supabase is not configured")) {
-          router.push("/studio/video/new");
-          return;
-        }
-        // Any other failure (unauth, server error) → send to sign-in
-        router.push(`/auth?next=${encodeURIComponent("/templates")}`);
-        return;
-      }
-
-      router.push(`/studio/video/${result.projectId}`);
-    },
-    [router, usingTemplateId]
-  );
+  // "Use this template" → open the template detail page (where the user picks
+  // aspect/style and starts an editable project). template.id is the slug.
+  const handleUseTemplate = (template: TemplateItem) => {
+    router.push(`/templates/${template.id}`);
+  };
 
   return (
     <section
@@ -172,8 +143,8 @@ export function TemplateGallery({ className, adminItems }: TemplateGalleryProps)
                   previewVideoUrl={template.previewVideoUrl}
                   previewSeed={template.id}
                   priority={filtered.indexOf(template) < 4}
-                  onUseTemplate={() => void handleUseTemplate(template)}
-                  isUsingTemplate={usingTemplateId === template.id}
+                  onUseTemplate={() => handleUseTemplate(template)}
+                  isUsingTemplate={false}
                   useTemplateLabel={t("useTemplate")}
                   openingLabel={t("opening")}
                 />