fix(blender,freecad): contain render in element, fix FreeCAD file serving

Blender: add wrapper with height:100%, min-height:0 for flex shrink,
object-fit:contain on img — render stays within shape bounds.

FreeCAD: update assembleFreecadResult to scan all tool results for file
paths (.step, .stl, .png), not just execute_python_script JSON parsing.
Add preview PNG rendering instruction to system prompt. Add subdirectory
file serving routes for /data/files/generated/:subdir/:filename. Add
STEP/STL/SVG/PDF mime types.

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

lib/folk-blender.ts

@@ -49,10 +49,18 @@ const styles = css`
 		background: rgba(255, 255, 255, 0.2);
 	}
 
+	.wrapper {
+		height: 100%;
+		overflow: hidden;
+		display: flex;
+		flex-direction: column;
+	}
+
 	.content {
 		display: flex;
 		flex-direction: column;
-		height: calc(100% - 36px);
+		flex: 1;
+		min-height: 0;
 		overflow: hidden;
 	}
 
@@ -136,6 +144,7 @@ const styles = css`
 
 	.preview-area {
 		flex: 1;
+		min-height: 0;
 		overflow: hidden;
 		display: flex;
 		flex-direction: column;
@@ -148,11 +157,13 @@ const styles = css`
 		justify-content: center;
 		padding: 12px;
 		overflow: hidden;
+		min-height: 0;
 	}
 
 	.render-preview img {
 		max-width: 100%;
 		max-height: 100%;
+		object-fit: contain;
 		border-radius: 8px;
 		box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
 	}
@@ -284,6 +295,7 @@ export class FolkBlender extends FolkShape {
 		const root = super.createRenderRoot();
 
 		const wrapper = document.createElement("div");
+		wrapper.className = "wrapper";
 		wrapper.innerHTML = html`
 			<div class="header">
 				<span class="header-title">

server/cad-orchestrator.ts

@@ -232,37 +232,35 @@ export function assembleFreecadResult(orch: OrchestrationResult): FreecadResult
 	let stepUrl: string | null = null;
 	let stlUrl: string | null = null;
 
+	// Scan ALL tool results for file paths (not just execute_python_script)
 	for (const entry of orch.toolCallLog) {
-		try {
+		const text = entry.result;
-			const parsed = JSON.parse(entry.result);
+
-			// FreeCAD exports via execute_python_script — look for file paths in results
+		// Extract preview image path
-			if (entry.tool === "execute_python_script" || entry.tool === "execute_script") {
+		if (!previewUrl) {
-				const text = entry.result.toLowerCase();
+			const pngPath = extractPathFromText(text, [".png", ".jpg", ".jpeg"]);
-				if (text.includes(".step") || text.includes(".stp")) {
+			if (pngPath) previewUrl = pngPath;
-					stepUrl = parsed.path || parsed.file_path || extractPathFromText(entry.result, [".step", ".stp"]);
+		}
-				}
+
-				if (text.includes(".stl")) {
+		// Extract STEP path
-					stlUrl = parsed.path || parsed.file_path || extractPathFromText(entry.result, [".stl"]);
+		if (!stepUrl) {
-				}
+			stepUrl = extractPathFromText(text, [".step", ".stp"]);
-			}
+		}
-			// save_document may also produce a path
+
-			if (entry.tool === "save_document") {
+		// Extract STL path
-				const path = parsed.path || parsed.file_path || null;
+		if (!stlUrl) {
-				if (path && (path.endsWith(".FCStd") || path.endsWith(".fcstd"))) {
+			stlUrl = extractPathFromText(text, [".stl"]);
-					// Not directly servable, but note it
-				}
-			}
-		} catch {
-			// Try extracting paths from raw text
-			stepUrl = stepUrl || extractPathFromText(entry.result, [".step", ".stp"]);
-			stlUrl = stlUrl || extractPathFromText(entry.result, [".stl"]);
 		}
 	}
 
+	// Convert internal paths to servable URLs
+	// /data/files/generated/... is served at /data/files/generated/...
+	const toUrl = (p: string | null) => p; // paths are already servable
+
 	return {
-		previewUrl,
+		previewUrl: toUrl(previewUrl),
-		stepUrl,
+		stepUrl: toUrl(stepUrl),
-		stlUrl,
+		stlUrl: toUrl(stlUrl),
 		summary: orch.finalMessage,
 		toolCallLog: orch.toolCallLog,
 	};
@@ -314,6 +312,17 @@ Follow this workflow:
 5. save_document to save the FreeCAD file
 6. execute_python_script to export STEP: Part.export([obj], "/data/files/generated/freecad-<id>/model.step")
 7. execute_python_script to export STL: Mesh.export([obj], "/data/files/generated/freecad-<id>/model.stl")
+8. execute_python_script to render a preview PNG (do this last, ignore errors if GUI unavailable):
+   try:
+       import FreeCADGui
+       FreeCADGui.showMainWindow()
+       view = FreeCADGui.ActiveDocument.ActiveView
+       view.viewIsometric()
+       view.fitAll()
+       view.saveImage("/data/files/generated/freecad-<id>/preview.png", 1024, 1024, "White")
+       print("/data/files/generated/freecad-<id>/preview.png")
+   except Exception as e:
+       print(f"Preview rendering not available: {e}")
 
 Important:
 - Use /data/files/generated/freecad-${Date.now()}/ as the working directory
@@ -321,4 +330,7 @@ Important:
 - For complex shapes, build up from primitives with boolean operations
 - Wall thickness should be at least 1mm for 3D printing
 - Always export both STEP (for CAD) and STL (for 3D printing)
+- Try to render a preview PNG as the final step — this is displayed to the user
+- When exporting files, always print() the FULL absolute path so it can be extracted from output
+- Example: after Part.export(...), add print("/data/files/generated/freecad-xxx/model.step")
 - If a tool call fails, try an alternative approach`;

server/index.ts

@@ -198,23 +198,37 @@ app.get("/collect.js", async (c) => {
 
 // ── Serve generated files from /data/files/generated/ and /api/files/generated/ ──
 // The /api/ route avoids Cloudflare/Traefik redirecting /data/ paths
+const GENERATED_MIME: Record<string, string> = {
+	png: "image/png", jpg: "image/jpeg", jpeg: "image/jpeg", webp: "image/webp",
+	glb: "model/gltf-binary", gltf: "model/gltf+json",
+	step: "application/step", stp: "application/step",
+	stl: "application/sla", fcstd: "application/octet-stream",
+	svg: "image/svg+xml", pdf: "application/pdf",
+};
+
 function serveGeneratedFile(c: any) {
+	// Support both flat files and subdirectory paths (e.g. freecad-xxx/model.step)
 	const filename = c.req.param("filename");
-	if (!filename || filename.includes("..") || filename.includes("/")) {
+	const subdir = c.req.param("subdir");
+	const relPath = subdir ? `${subdir}/${filename}` : filename;
+	if (!relPath || relPath.includes("..")) {
 		return c.json({ error: "Invalid filename" }, 400);
 	}
 	const dir = resolve(process.env.FILES_DIR || "./data/files", "generated");
-	const filePath = resolve(dir, filename);
+	const filePath = resolve(dir, relPath);
+	// Ensure resolved path stays within generated dir
+	if (!filePath.startsWith(dir)) return c.json({ error: "Invalid path" }, 400);
 	const file = Bun.file(filePath);
 	return file.exists().then((exists: boolean) => {
 		if (!exists) return c.notFound();
-		const ext = filename.split(".").pop() || "";
+		const ext = filePath.split(".").pop()?.toLowerCase() || "";
-		const mimeMap: Record<string, string> = { png: "image/png", jpg: "image/jpeg", jpeg: "image/jpeg", webp: "image/webp", glb: "model/gltf-binary", gltf: "model/gltf+json" };
+		return new Response(file, { headers: { "Content-Type": GENERATED_MIME[ext] || "application/octet-stream", "Cache-Control": "public, max-age=86400" } });
-		return new Response(file, { headers: { "Content-Type": mimeMap[ext] || "application/octet-stream", "Cache-Control": "public, max-age=86400" } });
 	});
 }
 app.get("/data/files/generated/:filename", serveGeneratedFile);
+app.get("/data/files/generated/:subdir/:filename", serveGeneratedFile);
 app.get("/api/files/generated/:filename", serveGeneratedFile);
+app.get("/api/files/generated/:subdir/:filename", serveGeneratedFile);
 
 // ── Link preview / unfurl API ──
 const linkPreviewCache = new Map<string, { title: string; description: string; image: string | null; domain: string; fetchedAt: number }>();