feat(rsplat): default to image upload + switch job queue to Hunyuan3D

- Default upload tab is now "Generate from Image"
- Entire dotted drop area is clickable to open file browser
- Update process3DGenJob to use Hunyuan3D v2.1 via fal.ai queue API
  (was still using old Trellis endpoint)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/index.ts

@@ -723,20 +723,20 @@ async function sendSplatEmail(job: Gen3DJob) {
 
 async function process3DGenJob(job: Gen3DJob) {
 	job.status = "processing";
-	try {
-		const res = await fetch("https://fal.run/fal-ai/trellis", {
-			method: "POST",
-			headers: {
-				Authorization: `Key ${FAL_KEY}`,
-				"Content-Type": "application/json",
-			},
-			body: JSON.stringify({ image_url: job.imageUrl }),
-		});
+	const falHeaders = { Authorization: `Key ${FAL_KEY}`, "Content-Type": "application/json" };
+	const MODEL = "fal-ai/hunyuan3d-v21";
 
-		if (!res.ok) {
-			const errText = await res.text();
-			console.error("[3d-gen] fal.ai error:", res.status, errText);
-			let detail = "3D generation failed";
+	try {
+		// 1. Submit to fal.ai queue
+		const submitRes = await fetch(`https://queue.fal.run/${MODEL}`, {
+			method: "POST",
+			headers: falHeaders,
+			body: JSON.stringify({ input_image_url: job.imageUrl, textured_mesh: true, octree_resolution: 256 }),
+		});
+		if (!submitRes.ok) {
+			const errText = await submitRes.text();
+			console.error("[3d-gen] fal.ai submit error:", submitRes.status, errText);
+			let detail = "3D generation failed to start";
 			try {
 				const parsed = JSON.parse(errText);
 				if (parsed.detail) {
@@ -750,9 +750,48 @@ async function process3DGenJob(job: Gen3DJob) {
 			job.completedAt = Date.now();
 			return;
 		}
+		const { request_id } = await submitRes.json() as { request_id: string };
 
-		const data = await res.json();
-		const modelUrl = data.glb_url || data.model_mesh?.url || data.output?.url;
+		// 2. Poll for completion (up to 5 min)
+		const deadline = Date.now() + 300_000;
+		let completed = false;
+		while (Date.now() < deadline) {
+			await new Promise((r) => setTimeout(r, 3000));
+			const statusRes = await fetch(
+				`https://queue.fal.run/${MODEL}/requests/${request_id}/status`,
+				{ headers: falHeaders },
+			);
+			if (!statusRes.ok) continue;
+			const status = await statusRes.json() as { status: string };
+			if (status.status === "COMPLETED") { completed = true; break; }
+			if (status.status === "FAILED") {
+				job.status = "failed";
+				job.error = "3D generation failed on fal.ai";
+				job.completedAt = Date.now();
+				return;
+			}
+		}
+		if (!completed) {
+			job.status = "failed";
+			job.error = "3D generation timed out";
+			job.completedAt = Date.now();
+			return;
+		}
+
+		// 3. Fetch result
+		const resultRes = await fetch(
+			`https://queue.fal.run/${MODEL}/requests/${request_id}`,
+			{ headers: falHeaders },
+		);
+		if (!resultRes.ok) {
+			job.status = "failed";
+			job.error = "Failed to retrieve 3D model";
+			job.completedAt = Date.now();
+			return;
+		}
+
+		const data = await resultRes.json();
+		const modelUrl = data.model_glb?.url || data.model_glb_pbr?.url;
 		if (!modelUrl) {
 			job.status = "failed";
 			job.error = "No 3D model returned";
@@ -760,6 +799,7 @@ async function process3DGenJob(job: Gen3DJob) {
 			return;
 		}
 
+		// 4. Download and save
 		const modelRes = await fetch(modelUrl);
 		if (!modelRes.ok) {
 			job.status = "failed";
@@ -769,14 +809,13 @@ async function process3DGenJob(job: Gen3DJob) {
 		}
 
 		const modelBuf = await modelRes.arrayBuffer();
-		const ext = modelUrl.includes(".ply") ? "ply" : "glb";
-		const filename = `splat-${Date.now()}-${Math.random().toString(36).slice(2, 6)}.${ext}`;
+		const filename = `splat-${Date.now()}-${Math.random().toString(36).slice(2, 6)}.glb`;
 		const dir = resolve(process.env.FILES_DIR || "./data/files", "generated");
 		await Bun.write(resolve(dir, filename), modelBuf);
 
 		job.status = "complete";
 		job.resultUrl = `/data/files/generated/${filename}`;
-		job.resultFormat = ext;
+		job.resultFormat = "glb";
 		job.completedAt = Date.now();
 		console.log(`[3d-gen] Job ${job.id} complete: ${job.resultUrl}`);
 
@@ -1171,7 +1210,7 @@ app.post("/api/image-stage", async (c) => {
 	return c.json({ url: `${PUBLIC_ORIGIN}/data/files/generated/${filename}` });
 });
 
-// Image-to-3D via fal.ai Trellis (async job queue)
+// Image-to-3D via fal.ai Hunyuan3D v2.1 (async job queue)
 app.post("/api/3d-gen", async (c) => {
 	if (!FAL_KEY) return c.json({ error: "FAL_KEY not configured" }, 503);