fix: scope sanity-revalidate webhook to skip pipeline doc types

The webhook was firing revalidateTag("sanity") on EVERY Sanity document
change, including automated pipeline documents (automatedVideo,
contentIdea, sponsorLead, etc.) that update frequently via cron jobs.
Each webhook call invalidated ALL cached pages simultaneously.

Now skips internal/pipeline document types that have no public-facing
pages. For public content types, keeps revalidateTag("sanity") as a
fallback for when no active visitors trigger SanityLive updates.

Skipped types: automatedVideo, contentIdea, sponsorLead,
pipeline_config, content_config

Co-authored-by: research <research@miriad.systems>

Author: Miriad

app/api/webhooks/sanity-revalidate/route.ts

@@ -23,10 +23,32 @@ export async function POST(request: NextRequest) {
 			);
 		}
 
-		// Revalidate all sanity-tagged caches (the "heavy hammer" approach)
-		// This is a backup for when no visitors are active to trigger SanityLive revalidation
-		// Next.js 16 requires a second argument — { expire: 0 } for immediate invalidation
-		revalidateTag("sanity", { expire: 0 });
+		// With defineLive + <SanityLive />, content pages get real-time updates
+		// without ISR revalidation. We only keep revalidateTag("sanity") as a
+		// fallback for when no active visitors are triggering live updates.
+		//
+		// IMPORTANT: Skip pipeline/internal document types that don't have
+		// public-facing pages. These fire frequently (every cron run) and
+		// were the primary cause of ISR write exhaustion.
+		const SKIP_TYPES = new Set([
+			"automatedVideo",
+			"contentIdea",
+			"sponsorLead",
+			"pipeline_config",
+			"content_config",
+		]);
+
+		if (SKIP_TYPES.has(body._type)) {
+			return NextResponse.json({
+				skipped: true,
+				type: body._type,
+				reason: "Internal document type — no revalidation needed",
+			});
+		}
+
+		// For public content types, revalidate the sanity tag as a fallback.
+		// This only affects pages that still use Next.js cache tags (e.g., sitemap).
+		revalidateTag("sanity");
 
 		return NextResponse.json({
 			revalidated: true,