fix: handle non-image modalities across uploads, previews, and filenames (#255)

SnapOtter spans five modalities now, but several code paths still assumed image input.

- dropzone: default to accept-all when no fileFilter is given (image tools still pass one); neutral "supported file types" error text instead of "image files"
- automate (pipelines): accept any modality in the file pickers and dropzones; render modality-aware previews (video player, audio waveform, document/data card) instead of always using ImageViewer/BeforeAfterSlider
- filename sanitizer: extend the double-extension allowlist beyond image extensions to video/audio/document/data so e.g. "report.csv.php" becomes "report.csv"; add tests
- thumbnail route: return 422 for non-rasterisable files (audio, data, non-PDF docs) instead of attempting a doomed Sharp decode
- pool: unknown tools fall back to the "system" pool, not the image pool
- a11y labels: "Previous/Next image", "Image viewer/area/controls/drop zone" are now modality-neutral, across all 21 locales
- copy: bulk-rename default, find-duplicates ZIP name, SSRF user-agent, fetch-urls fallback name, file-details MIME label, URL-import placeholder, help dialog

apps/api/src/lib/filename.ts

@@ -1,6 +1,10 @@
 import { basename } from "node:path";
 
-const SAFE_IMAGE_EXTENSIONS = new Set([
+// Recognised, safe file extensions across all five modalities (image, video,
+// audio, document, data). Used to truncate double-extension attacks after the
+// first known-good extension, e.g. "report.csv.php" becomes "report.csv".
+const SAFE_EXTENSIONS = new Set([
+  // Image
   ".jpg",
   ".jpeg",
   ".png",
@@ -11,7 +15,65 @@ const SAFE_IMAGE_EXTENSIONS = new Set([
   ".tif",
   ".avif",
   ".svg",
+  ".heic",
+  ".heif",
+  ".jxl",
+  ".ico",
+  ".jp2",
+  ".qoi",
+  ".psd",
+  ".dng",
+  // Video
+  ".mp4",
+  ".webm",
+  ".mov",
+  ".mkv",
+  ".avi",
+  ".m4v",
+  ".mpg",
+  ".mpeg",
+  ".wmv",
+  ".flv",
+  ".ogv",
+  // Audio
+  ".mp3",
+  ".wav",
+  ".flac",
+  ".ogg",
+  ".oga",
+  ".aac",
+  ".m4a",
+  ".opus",
+  ".wma",
+  ".aiff",
+  ".aif",
+  // Document
   ".pdf",
+  ".doc",
+  ".docx",
+  ".odt",
+  ".rtf",
+  ".txt",
+  ".md",
+  ".markdown",
+  ".html",
+  ".htm",
+  ".epub",
+  ".ppt",
+  ".pptx",
+  ".odp",
+  ".xls",
+  ".xlsx",
+  ".ods",
+  // Data
+  ".csv",
+  ".tsv",
+  ".json",
+  ".xml",
+  ".yaml",
+  ".yml",
+  ".zip",
+  ".srt",
 ]);
 
 /**
@@ -19,8 +81,8 @@ const SAFE_IMAGE_EXTENSIONS = new Set([
  *
  * 1. Strips directory separators (basename only).
  * 2. Removes ".." sequences and null bytes.
- * 3. Truncates after the first recognised image extension so that
- *    "photo.png.php" becomes "photo.png".
+ * 3. Truncates after the first recognised file extension so that
+ *    "report.csv.php" becomes "report.csv".
  */
 export function sanitizeFilename(raw: string): string {
   let name = basename(raw);
@@ -30,14 +92,14 @@ export function sanitizeFilename(raw: string): string {
     name = "upload";
   }
 
-  // Guard against double-extension attacks (e.g. "image.png.php").
-  // Walk the dot-separated parts and truncate after the first safe image extension.
+  // Guard against double-extension attacks (e.g. "report.csv.php").
+  // Walk the dot-separated parts and truncate after the first safe extension.
   const dotIndex = name.indexOf(".");
   if (dotIndex !== -1) {
     const parts = name.split(".");
     for (let i = 1; i < parts.length; i++) {
       const ext = `.${parts[i].toLowerCase()}`;
-      if (SAFE_IMAGE_EXTENSIONS.has(ext)) {
+      if (SAFE_EXTENSIONS.has(ext)) {
         // Keep everything up to and including this extension, drop the rest
         name = parts.slice(0, i + 1).join(".");
         break;

apps/api/src/lib/pool.ts

@@ -6,7 +6,9 @@ import type { Pool } from "../jobs/types.js";
 export function resolveToolPool(toolId: string): Pool {
   if (hasAiJobHandler(toolId) || TOOL_BUNDLE_MAP[toolId]) return "ai";
   const tool = TOOLS.find((t) => t.id === toolId);
-  return tool ? MODALITY_POOL[tool.modality] : "image";
+  // Unknown tools fall back to the general-purpose "system" pool rather than
+  // assuming the image pool (a legacy image-only default).
+  return tool ? MODALITY_POOL[tool.modality] : "system";
 }
 
 export function shouldSkipSyncWindow(executionHint: "fast" | "long" | undefined): boolean {

apps/api/src/lib/ssrf.ts

@@ -158,7 +158,7 @@ export async function safeFetch(url: string, signal?: AbortSignal): Promise<Resp
       signal,
       redirect: "manual",
       headers: {
-        "User-Agent": "SnapOtter/1.0 (image-fetch)",
+        "User-Agent": "SnapOtter/2.0 (file-fetch)",
         Host: parsed.host,
       },
     };
@@ -176,7 +176,7 @@ export async function safeFetch(url: string, signal?: AbortSignal): Promise<Resp
             agent,
             signal: signal ?? undefined,
             headers: {
-              "User-Agent": "SnapOtter/1.0 (image-fetch)",
+              "User-Agent": "SnapOtter/2.0 (file-fetch)",
             },
             method: "GET",
           },

apps/api/src/routes/fetch-urls.ts

@@ -110,7 +110,7 @@ function filenameFromUrl(url: string): string {
   } catch {
     // ignore parse errors
   }
-  return `image-${randomUUID().slice(0, 8)}`;
+  return `file-${randomUUID().slice(0, 8)}`;
 }
 
 /**

apps/api/src/routes/user-files.ts

@@ -524,6 +524,12 @@ export async function userFileRoutes(app: FastifyInstance): Promise<void> {
 
         // Image thumbnail (existing path)
         const validation = await validateImageBuffer(rawBuffer, file.originalName);
+        if (!validation.valid) {
+          // Audio, data, and non-PDF document files have no raster thumbnail.
+          // Return 422 (not 204) so the client's <img> onError falls back to a
+          // modality icon instead of attempting a doomed Sharp decode below.
+          return reply.status(422).send({ error: "No thumbnail available for this file type" });
+        }
         let decoded: Buffer<ArrayBuffer> = Buffer.from(rawBuffer);
         if (validation.valid && validation.format === "heif") {
           decoded = Buffer.from(await decodeHeic(rawBuffer));