feat: add format tools (SVG-to-raster, vectorize, GIF) and optimization (rename, favicon, image-to-PDF)

Add 6 tools for format conversion and optimization extras:
- svg-to-raster: SVG to PNG/JPG/WebP at custom resolution
- vectorize: raster to SVG via potrace (B&W and color modes)
- gif-tools: animated GIF resize, frame extraction, optimization
- bulk-rename: pattern-based file renaming with ZIP output
- favicon: generate all favicon/app icon sizes with manifest.json
- image-to-pdf: combine images into PDF using pdfkit

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

@@ -0,0 +1,47 @@
+import { z } from "zod";
+import { createToolRoute } from "../tool-factory.js";
+import sharp from "sharp";
+import type { FastifyInstance } from "fastify";
+
+const settingsSchema = z.object({
+  width: z.number().min(1).max(4096).optional(),
+  height: z.number().min(1).max(4096).optional(),
+  extractFrame: z.number().min(0).optional(),
+  optimize: z.boolean().default(false),
+});
+
+export function registerGifTools(app: FastifyInstance) {
+  createToolRoute(app, {
+    toolId: "gif-tools",
+    settingsSchema,
+    process: async (inputBuffer, settings, filename) => {
+      if (settings.extractFrame !== undefined) {
+        // Extract a single frame from animated GIF
+        const image = sharp(inputBuffer, { page: settings.extractFrame });
+
+        if (settings.width || settings.height) {
+          image.resize(settings.width, settings.height, { fit: "inside" });
+        }
+
+        const buffer = await image.png().toBuffer();
+        const outName = filename.replace(/\.gif$/i, "") + `_frame${settings.extractFrame}.png`;
+        return { buffer, filename: outName, contentType: "image/png" };
+      }
+
+      // Process animated GIF (preserve animation)
+      const image = sharp(inputBuffer, { animated: true });
+
+      if (settings.width || settings.height) {
+        image.resize(settings.width, settings.height, { fit: "inside" });
+      }
+
+      if (settings.optimize) {
+        // Reduce colors for optimization
+        image.gif({ effort: 10 });
+      }
+
+      const buffer = await image.gif().toBuffer();
+      return { buffer, filename, contentType: "image/gif" };
+    },
+  });
+}