fix(shell): evict tab pane from cache on script load failure

When a module script (e.g. canvas-*.js) fails to load (502 during
deploy, network error), the pane stayed in cache with a blank canvas.
Subsequent tab switches showed the broken cached pane instead of
re-fetching. Now script onerror removes the failed tag and evicts
the pane, so the next switchTo does a fresh fetch.

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

docker-compose.yml

@@ -282,6 +282,16 @@ services:
     networks:
       - rspace-internal
 
+  # ── Blender headless render worker ──
+  blender-worker:
+    build: ./docker/blender-worker
+    container_name: blender-worker
+    restart: unless-stopped
+    volumes:
+      - rspace-files:/data/files
+    networks:
+      - rspace-internal
+
   # ── Scribus noVNC (rDesign DTP workspace) ──
   scribus-novnc:
     build:

docker/blender-worker/Dockerfile

@@ -0,0 +1,20 @@
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    blender \
+    python3 \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+ENV QT_QPA_PLATFORM=offscreen
+ENV DISPLAY=""
+
+WORKDIR /app
+
+COPY server.py .
+
+RUN mkdir -p /data/files/generated
+
+EXPOSE 8810
+
+CMD ["python3", "server.py"]

docker/blender-worker/server.py

@@ -0,0 +1,104 @@
+"""Headless Blender render worker — accepts scripts via HTTP, returns rendered images."""
+
+import json
+import os
+import random
+import string
+import subprocess
+import time
+from http.server import HTTPServer, BaseHTTPRequestHandler
+
+GENERATED_DIR = "/data/files/generated"
+BLENDER_TIMEOUT = 90  # seconds (fits within CF 100s limit)
+
+
+class RenderHandler(BaseHTTPRequestHandler):
+    def do_GET(self):
+        if self.path == "/health":
+            self._json_response(200, {"ok": True, "service": "blender-worker"})
+        else:
+            self._json_response(404, {"error": "not found"})
+
+    def do_POST(self):
+        if self.path != "/render":
+            self._json_response(404, {"error": "not found"})
+            return
+
+        try:
+            length = int(self.headers.get("Content-Length", 0))
+            body = json.loads(self.rfile.read(length))
+        except (json.JSONDecodeError, ValueError):
+            self._json_response(400, {"error": "invalid JSON"})
+            return
+
+        script = body.get("script", "").strip()
+        if not script:
+            self._json_response(400, {"error": "script required"})
+            return
+
+        # Write script to temp file
+        script_path = "/tmp/scene.py"
+        render_path = "/tmp/render.png"
+
+        with open(script_path, "w") as f:
+            f.write(script)
+
+        # Clean any previous render
+        if os.path.exists(render_path):
+            os.remove(render_path)
+
+        # Run Blender headless
+        try:
+            result = subprocess.run(
+                ["blender", "--background", "--python", script_path],
+                capture_output=True,
+                text=True,
+                timeout=BLENDER_TIMEOUT,
+            )
+        except subprocess.TimeoutExpired:
+            self._json_response(504, {
+                "success": False,
+                "error": f"Blender timed out after {BLENDER_TIMEOUT}s",
+            })
+            return
+
+        # Check if render was produced
+        if not os.path.exists(render_path):
+            self._json_response(422, {
+                "success": False,
+                "error": "Blender finished but no render output at /tmp/render.png",
+                "stdout": result.stdout[-2000:] if result.stdout else "",
+                "stderr": result.stderr[-2000:] if result.stderr else "",
+            })
+            return
+
+        # Move render to shared volume with unique name
+        rand = "".join(random.choices(string.ascii_lowercase + string.digits, k=6))
+        filename = f"blender-{int(time.time())}-{rand}.png"
+        dest = os.path.join(GENERATED_DIR, filename)
+
+        os.makedirs(GENERATED_DIR, exist_ok=True)
+        os.rename(render_path, dest)
+
+        self._json_response(200, {
+            "success": True,
+            "render_url": f"/data/files/generated/{filename}",
+            "filename": filename,
+        })
+
+    def _json_response(self, status, data):
+        body = json.dumps(data).encode("utf-8")
+        self.send_response(status)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def log_message(self, fmt, *args):
+        print(f"[blender-worker] {fmt % args}")
+
+
+if __name__ == "__main__":
+    server = HTTPServer(("0.0.0.0", 8810), RenderHandler)
+    print("[blender-worker] listening on :8810")
+    server.serve_forever()

server/index.ts

@@ -1550,14 +1550,22 @@ app.get("/api/3d-gen/:jobId", async (c) => {
 	return c.json(response);
 });
 
-// Blender 3D generation via LLM + RunPod
-const RUNPOD_API_KEY = process.env.RUNPOD_API_KEY || "";
+// Blender 3D generation via LLM + headless worker sidecar
+const BLENDER_WORKER_URL = process.env.BLENDER_WORKER_URL || "http://blender-worker:8810";
 
 app.get("/api/blender-gen/health", async (c) => {
 	const issues: string[] = [];
 	const warnings: string[] = [];
 	if (!GEMINI_API_KEY) issues.push("GEMINI_API_KEY not configured");
-	if (!RUNPOD_API_KEY) warnings.push("RunPod not configured — script-only mode");
+
+	// Check blender-worker health
+	try {
+		const res = await fetch(`${BLENDER_WORKER_URL}/health`, { signal: AbortSignal.timeout(3000) });
+		if (!res.ok) warnings.push("blender-worker unhealthy");
+	} catch {
+		warnings.push("blender-worker unreachable — script-only mode");
+	}
+
 	return c.json({ available: issues.length === 0, issues, warnings });
 });
 
@@ -1596,38 +1604,37 @@ Output ONLY the Python code, no explanations or comments outside the code.`);
 		return c.json({ error: "Failed to generate Blender script" }, 502);
 	}
 
-	// Step 2: Execute on RunPod (headless Blender) — optional
-	if (!RUNPOD_API_KEY) {
-		return c.json({ script, render_url: null, blend_url: null });
-	}
-
+	// Step 2: Execute on blender-worker sidecar (headless Blender)
 	try {
-		const runpodRes = await fetch("https://api.runpod.ai/v2/blender/runsync", {
+		const workerRes = await fetch(`${BLENDER_WORKER_URL}/render`, {
 			method: "POST",
-			headers: {
-				Authorization: `Bearer ${RUNPOD_API_KEY}`,
-				"Content-Type": "application/json",
-			},
-			body: JSON.stringify({
-				input: {
-					script,
-					render: true,
-				},
-			}),
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({ script }),
+			signal: AbortSignal.timeout(95_000), // 95s — worker has 90s internal timeout
 		});
 
-		if (!runpodRes.ok) {
-			return c.json({ script, error_detail: "RunPod execution failed" });
+		const data = await workerRes.json() as {
+			success?: boolean;
+			render_url?: string;
+			error?: string;
+			stdout?: string;
+			stderr?: string;
+		};
+
+		if (data.success && data.render_url) {
+			return c.json({ script, render_url: data.render_url });
 		}
 
-		const runpodData = await runpodRes.json();
+		// Worker ran but render failed — return script + error details
 		return c.json({
-			render_url: runpodData.output?.render_url || null,
 			script,
-			blend_url: runpodData.output?.blend_url || null,
+			render_url: null,
+			error_detail: data.error || "Render failed",
 		});
 	} catch (e) {
-		return c.json({ script, error_detail: "RunPod unavailable" });
+		console.error("[blender-gen] worker error:", e);
+		// Worker unreachable — return script only
+		return c.json({ script, render_url: null, error_detail: "blender-worker unavailable" });
 	}
 });
 

shared/tab-cache.ts

@@ -344,6 +344,22 @@ export class TabCache {
 			const el = document.createElement("script");
 			el.type = "module";
 			el.src = src;
+			// If a script fails (502, network error), evict the pane from cache
+			// so the next switchTo re-fetches everything instead of showing a blank pane.
+			el.onerror = () => {
+				console.warn("[TabCache] script load failed:", src, "— evicting pane", moduleId);
+				el.remove();
+				if (moduleId) {
+					// moduleId here is "space-module" format — find and remove the pane
+					for (const [key, pane] of this.panes) {
+						if (pane.dataset.moduleId && moduleId.endsWith(pane.dataset.moduleId)) {
+							pane.remove();
+							this.panes.delete(key);
+							break;
+						}
+					}
+				}
+			};
 			document.body.appendChild(el);
 		}