fix: resolve 18 QA-discovered bugs across tools, previews, and the AI pipeline (#242)

Exhaustive QA sweep of all 157 tools. Fixes: CSP blob media, csv-excel ExcelJS interop, ocr-pdf segfault, chart-maker upload, non-PDF doc preview, RAW decode, merge-tool multi-file path, html-to-image chromium, ogv/wma/amr/ac3 preview fallbacks, meme/gif/stabilize codecs, nav+home a11y. Plus orphan-format and test-debt cleanup, the AI bundle build script, and a reusable Playwright QA harness under tests/qa/.

apps/api/src/routes/tools/csv-excel.ts

@@ -20,8 +20,10 @@ export function registerCsvExcel(app: FastifyInstance) {
       const base = input.filename.replace(/\.[^.]+$/, "");
       const lower = input.filename.toLowerCase();
 
-      // Dynamic import: exceljs is heavy; load it only when this tool runs
-      const ExcelJS = await import("exceljs");
+      // Dynamic import: exceljs is heavy; load it only when this tool runs.
+      // exceljs is CJS, so under ESM the constructor lives on the default export
+      // (namespace `.Workbook` is undefined -> "is not a constructor").
+      const { default: ExcelJS } = await import("exceljs");
 
       if (lower.endsWith(".xlsx")) {
         // xlsx -> csv: load workbook, pick the Nth worksheet, extract rows

apps/api/src/routes/tools/meme-generator.ts

@@ -170,9 +170,20 @@ async function processMeme(
     gif: "image/gif",
   };
 
+  // Ensure the output filename extension matches the actual raster format
+  // (e.g. SVG input produces a PNG buffer, so the name must end in .png).
+  const extMap: Record<string, string> = {
+    jpeg: ".jpg",
+    png: ".png",
+    webp: ".webp",
+    gif: ".gif",
+  };
+  const correctExt = extMap[detectedFormat] ?? ".png";
+  const outFilename = filename.replace(/\.[^.]+$/, correctExt);
+
   return {
     buffer: result,
-    filename,
+    filename: outFilename,
     contentType: mimeMap[detectedFormat] ?? "image/png",
   };
 }

apps/api/src/routes/tools/stabilize-video.ts

@@ -1,5 +1,5 @@
 import { extname, join } from "node:path";
-import { probeMedia, resolveEncoder, runFfmpeg } from "@snapotter/media-engine";
+import { type EncoderTarget, probeMedia, resolveEncoder, runFfmpeg } from "@snapotter/media-engine";
 import type { FastifyInstance } from "fastify";
 import { z } from "zod";
 import { runFfmpegWithProgress, stageMediaInputs, videoContentType } from "../../lib/media-tool.js";
@@ -9,6 +9,44 @@ const settingsSchema = z.object({
   smoothing: z.number().int().min(5).max(60).default(15),
 });
 
+/**
+ * Choose a codec that is valid for the given container extension.
+ * webm requires VP9 (or VP8/AV1); ogv requires Theora; everything
+ * else gets H.264 (mp4/mov/mkv/avi/ts).
+ */
+function codecForContainer(ext: string): {
+  target: EncoderTarget;
+  encodeArgs: string[];
+} {
+  const lower = ext.toLowerCase();
+  if (lower === ".webm") {
+    return {
+      target: "vp9",
+      encodeArgs: ["-c:v", resolveEncoder("vp9"), "-crf", "30", "-b:v", "0", "-row-mt", "1"],
+    };
+  }
+  if (lower === ".ogv" || lower === ".ogg") {
+    // Theora has no HW-accel path; use libtheora directly.
+    return {
+      target: "h264", // unused, just for the type
+      encodeArgs: ["-c:v", "libtheora", "-q:v", "7"],
+    };
+  }
+  return {
+    target: "h264",
+    encodeArgs: [
+      "-c:v",
+      resolveEncoder("h264"),
+      "-crf",
+      "20",
+      "-preset",
+      "medium",
+      "-pix_fmt",
+      "yuv420p",
+    ],
+  };
+}
+
 export function registerStabilizeVideo(app: FastifyInstance) {
   createToolRoute(app, {
     toolId: "stabilize-video",
@@ -38,9 +76,19 @@ export function registerStabilizeVideo(app: FastifyInstance) {
         },
       );
 
-      // Pass 2: stabilization with re-encode
+      // Pass 2: stabilization with re-encode using a container-appropriate codec.
       ctx.report(50, "Stabilizing");
       const outPath = join(ctx.scratchDir, "media", outName);
+      const { encodeArgs } = codecForContainer(origExt);
+
+      // Audio: webm/ogv need Opus/Vorbis; for other containers just copy.
+      const audioArgs =
+        origExt.toLowerCase() === ".webm"
+          ? ["-c:a", resolveEncoder("opus")]
+          : origExt.toLowerCase() === ".ogv" || origExt.toLowerCase() === ".ogg"
+            ? ["-c:a", "libvorbis"]
+            : ["-c:a", "copy"];
+
       await runFfmpegWithProgress(
         ctx,
         [
@@ -48,16 +96,8 @@ export function registerStabilizeVideo(app: FastifyInstance) {
           inPath,
           "-vf",
           `vidstabtransform=input=${trf}:smoothing=${settings.smoothing}`,
-          "-c:v",
-          resolveEncoder("h264"),
-          "-crf",
-          "20",
-          "-preset",
-          "medium",
-          "-pix_fmt",
-          "yuv420p",
-          "-c:a",
-          "copy",
+          ...encodeArgs,
+          ...audioArgs,
           outPath,
         ],
         info.durationS,

apps/api/src/routes/tools/video-to-gif.ts

@@ -23,13 +23,19 @@ export function registerVideoToGif(app: FastifyInstance) {
       const outName = `${base}.gif`;
 
       const { outPath } = await runMediaTool(ctx, outName, (inPath, out) => {
+        // Place -ss/-t AFTER -i (output-side seeking) so ffmpeg decodes
+        // from the start.  Input-side seeking relies on a keyframe index
+        // which FLV (and some other legacy containers) often lack, causing
+        // zero decoded frames and exit 234.
         return [
+          "-fflags",
+          "+genpts",
+          "-i",
+          inPath,
           "-ss",
           String(settings.startS),
           "-t",
           String(settings.durationS),
-          "-i",
-          inPath,
           "-vf",
           `fps=${settings.fps},scale=${settings.width}:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse`,
           out,