feat: add replace-color tool and update tool page routing

- Add replace-color tool with pixel-level color replacement and tolerance
- Register all 19 new Phase 3 tools in routes/tools/index.ts
- Map all new tool IDs to settings components in tool-page.tsx
- Add PDF, ZIP, ICO, JSON content types to download route
- Install qrcode, jsqr, potrace, pdfkit dependencies

apps/api/package.json

@@ -24,7 +24,11 @@
     "dotenv": "^16.4.0",
     "drizzle-orm": "^0.38.0",
     "fastify": "^5.2.0",
+    "jsqr": "^1.4.0",
     "p-queue": "^9.1.0",
+    "pdfkit": "^0.18.0",
+    "potrace": "^2.1.8",
+    "qrcode": "^1.5.4",
     "sharp": "^0.33.0",
     "zod": "^3.24.0"
   },
@@ -32,6 +36,9 @@
     "@types/archiver": "^7.0.0",
     "@types/better-sqlite3": "^7.6.0",
     "@types/node": "^22.0.0",
+    "@types/pdfkit": "^0.17.5",
+    "@types/potrace": "^2.1.5",
+    "@types/qrcode": "^1.5.6",
     "drizzle-kit": "^0.30.0",
     "tsx": "^4.19.0",
     "typescript": "^5.7.0"

apps/api/src/routes/files.ts

@@ -157,6 +157,10 @@ function getContentType(ext: string): string {
     tif: "image/tiff",
     avif: "image/avif",
     svg: "image/svg+xml",
+    pdf: "application/pdf",
+    zip: "application/zip",
+    ico: "image/x-icon",
+    json: "application/json",
   };
   return map[ext] ?? "application/octet-stream";
 }

apps/api/src/routes/tools/index.ts

@@ -6,12 +6,39 @@ import { registerConvert } from "./convert.js";
 import { registerCompress } from "./compress.js";
 import { registerStripMetadata } from "./strip-metadata.js";
 import { registerColorAdjustments } from "./color-adjustments.js";
+// Phase 3: Watermark & Overlay
+import { registerWatermarkText } from "./watermark-text.js";
+import { registerWatermarkImage } from "./watermark-image.js";
+import { registerTextOverlay } from "./text-overlay.js";
+import { registerCompose } from "./compose.js";
+// Phase 3: Utilities
+import { registerInfo } from "./info.js";
+import { registerCompare } from "./compare.js";
+import { registerFindDuplicates } from "./find-duplicates.js";
+import { registerColorPalette } from "./color-palette.js";
+import { registerQrGenerate } from "./qr-generate.js";
+import { registerBarcodeRead } from "./barcode-read.js";
+// Phase 3: Layout & Composition
+import { registerCollage } from "./collage.js";
+import { registerSplit } from "./split.js";
+import { registerBorder } from "./border.js";
+// Phase 3: Format & Conversion
+import { registerSvgToRaster } from "./svg-to-raster.js";
+import { registerVectorize } from "./vectorize.js";
+import { registerGifTools } from "./gif-tools.js";
+// Phase 3: Optimization extras
+import { registerBulkRename } from "./bulk-rename.js";
+import { registerFavicon } from "./favicon.js";
+import { registerImageToPdf } from "./image-to-pdf.js";
+// Phase 3: Adjustments extra
+import { registerReplaceColor } from "./replace-color.js";
 
 /**
  * Registry that imports and registers all tool routes.
  * Each tool uses the createToolRoute factory from tool-factory.ts.
  */
 export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
+  // Phase 2: Core tools
   registerResize(app);
   registerCrop(app);
   registerRotate(app);
@@ -20,5 +47,37 @@ export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
   registerStripMetadata(app);
   registerColorAdjustments(app);
 
-  app.log.info("Tool routes registered (7 tools, 10 endpoints)");
+  // Phase 3: Watermark & Overlay
+  registerWatermarkText(app);
+  registerWatermarkImage(app);
+  registerTextOverlay(app);
+  registerCompose(app);
+
+  // Phase 3: Utilities
+  registerInfo(app);
+  registerCompare(app);
+  registerFindDuplicates(app);
+  registerColorPalette(app);
+  registerQrGenerate(app);
+  registerBarcodeRead(app);
+
+  // Phase 3: Layout & Composition
+  registerCollage(app);
+  registerSplit(app);
+  registerBorder(app);
+
+  // Phase 3: Format & Conversion
+  registerSvgToRaster(app);
+  registerVectorize(app);
+  registerGifTools(app);
+
+  // Phase 3: Optimization extras
+  registerBulkRename(app);
+  registerFavicon(app);
+  registerImageToPdf(app);
+
+  // Phase 3: Adjustments extra
+  registerReplaceColor(app);
+
+  app.log.info("Tool routes registered (26 tools, 29 endpoints)");
 }

apps/api/src/routes/tools/replace-color.ts

@@ -0,0 +1,71 @@
+import { z } from "zod";
+import { createToolRoute } from "../tool-factory.js";
+import sharp from "sharp";
+import type { FastifyInstance } from "fastify";
+
+const settingsSchema = z.object({
+  sourceColor: z.string().regex(/^#[0-9a-fA-F]{6}$/).default("#FF0000"),
+  targetColor: z.string().regex(/^#[0-9a-fA-F]{6}$/).default("#00FF00"),
+  makeTransparent: z.boolean().default(false),
+  tolerance: z.number().min(0).max(255).default(30),
+});
+
+function hexToRgb(hex: string): { r: number; g: number; b: number } {
+  return {
+    r: parseInt(hex.slice(1, 3), 16),
+    g: parseInt(hex.slice(3, 5), 16),
+    b: parseInt(hex.slice(5, 7), 16),
+  };
+}
+
+function colorDistance(
+  r1: number, g1: number, b1: number,
+  r2: number, g2: number, b2: number,
+): number {
+  return Math.sqrt((r1 - r2) ** 2 + (g1 - g2) ** 2 + (b1 - b2) ** 2);
+}
+
+export function registerReplaceColor(app: FastifyInstance) {
+  createToolRoute(app, {
+    toolId: "replace-color",
+    settingsSchema,
+    process: async (inputBuffer, settings, filename) => {
+      const source = hexToRgb(settings.sourceColor);
+      const target = hexToRgb(settings.targetColor);
+
+      // Get raw RGBA pixels
+      const image = sharp(inputBuffer).ensureAlpha();
+      const { data, info } = await image.raw().toBuffer({ resolveWithObject: true });
+
+      const pixels = Buffer.from(data);
+      const maxDist = settings.tolerance * 1.73; // sqrt(3) for RGB distance scaling
+
+      for (let i = 0; i < pixels.length; i += 4) {
+        const dist = colorDistance(
+          pixels[i], pixels[i + 1], pixels[i + 2],
+          source.r, source.g, source.b,
+        );
+
+        if (dist <= maxDist) {
+          if (settings.makeTransparent) {
+            pixels[i + 3] = 0; // Make transparent
+          } else {
+            // Blend: closer to source color = more of target color
+            const blend = 1 - dist / maxDist;
+            pixels[i] = Math.round(pixels[i] * (1 - blend) + target.r * blend);
+            pixels[i + 1] = Math.round(pixels[i + 1] * (1 - blend) + target.g * blend);
+            pixels[i + 2] = Math.round(pixels[i + 2] * (1 - blend) + target.b * blend);
+          }
+        }
+      }
+
+      const buffer = await sharp(pixels, {
+        raw: { width: info.width, height: info.height, channels: 4 },
+      })
+        .png()
+        .toBuffer();
+
+      return { buffer, filename, contentType: "image/png" };
+    },
+  });
+}

apps/web/src/components/tools/replace-color-settings.tsx

@@ -0,0 +1,85 @@
+import { useState } from "react";
+import { useFileStore } from "@/stores/file-store";
+import { useToolProcessor } from "@/hooks/use-tool-processor";
+import { Download, Loader2 } from "lucide-react";
+
+export function ReplaceColorSettings() {
+  const { files } = useFileStore();
+  const { processFiles, processing, error, downloadUrl, originalSize, processedSize } =
+    useToolProcessor("replace-color");
+
+  const [sourceColor, setSourceColor] = useState("#FF0000");
+  const [targetColor, setTargetColor] = useState("#00FF00");
+  const [makeTransparent, setMakeTransparent] = useState(false);
+  const [tolerance, setTolerance] = useState(30);
+
+  const handleProcess = () => {
+    processFiles(files, { sourceColor, targetColor, makeTransparent, tolerance });
+  };
+
+  const hasFile = files.length > 0;
+
+  return (
+    <div className="space-y-4">
+      <div>
+        <label className="text-xs text-muted-foreground">Source Color (to replace)</label>
+        <div className="flex items-center gap-2 mt-0.5">
+          <input type="color" value={sourceColor} onChange={(e) => setSourceColor(e.target.value)} className="w-10 h-8 rounded border border-border" />
+          <span className="text-xs font-mono text-foreground">{sourceColor}</span>
+        </div>
+      </div>
+
+      <label className="flex items-center gap-2 text-sm text-foreground">
+        <input type="checkbox" checked={makeTransparent} onChange={(e) => setMakeTransparent(e.target.checked)} className="rounded" />
+        Make transparent instead
+      </label>
+
+      {!makeTransparent && (
+        <div>
+          <label className="text-xs text-muted-foreground">Target Color (replacement)</label>
+          <div className="flex items-center gap-2 mt-0.5">
+            <input type="color" value={targetColor} onChange={(e) => setTargetColor(e.target.value)} className="w-10 h-8 rounded border border-border" />
+            <span className="text-xs font-mono text-foreground">{targetColor}</span>
+          </div>
+        </div>
+      )}
+
+      <div>
+        <div className="flex justify-between items-center">
+          <label className="text-xs text-muted-foreground">Tolerance</label>
+          <span className="text-xs font-mono text-foreground">{tolerance}</span>
+        </div>
+        <input type="range" min={0} max={255} value={tolerance} onChange={(e) => setTolerance(Number(e.target.value))} className="w-full mt-1" />
+        <div className="flex justify-between text-[10px] text-muted-foreground mt-0.5">
+          <span>Exact match</span>
+          <span>Wide range</span>
+        </div>
+      </div>
+
+      {error && <p className="text-xs text-red-500">{error}</p>}
+
+      {originalSize != null && processedSize != null && (
+        <div className="text-xs text-muted-foreground space-y-0.5">
+          <p>Original: {(originalSize / 1024).toFixed(1)} KB</p>
+          <p>Processed: {(processedSize / 1024).toFixed(1)} KB</p>
+        </div>
+      )}
+
+      <button
+        onClick={handleProcess}
+        disabled={!hasFile || processing}
+        className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
+      >
+        {processing && <Loader2 className="h-4 w-4 animate-spin" />}
+        {processing ? "Processing..." : "Replace Color"}
+      </button>
+
+      {downloadUrl && (
+        <a href={downloadUrl} download className="w-full py-2.5 rounded-lg border border-primary text-primary font-medium flex items-center justify-center gap-2 hover:bg-primary/5">
+          <Download className="h-4 w-4" />
+          Download
+        </a>
+      )}
+    </div>
+  );
+}

apps/web/src/pages/tool-page.tsx

@@ -12,6 +12,32 @@ import { ConvertSettings } from "@/components/tools/convert-settings";
 import { CompressSettings } from "@/components/tools/compress-settings";
 import { StripMetadataSettings } from "@/components/tools/strip-metadata-settings";
 import { ColorSettings } from "@/components/tools/color-settings";
+// Phase 3: Watermark & Overlay
+import { WatermarkTextSettings } from "@/components/tools/watermark-text-settings";
+import { WatermarkImageSettings } from "@/components/tools/watermark-image-settings";
+import { TextOverlaySettings } from "@/components/tools/text-overlay-settings";
+import { ComposeSettings } from "@/components/tools/compose-settings";
+// Phase 3: Utilities
+import { InfoSettings } from "@/components/tools/info-settings";
+import { CompareSettings } from "@/components/tools/compare-settings";
+import { FindDuplicatesSettings } from "@/components/tools/find-duplicates-settings";
+import { ColorPaletteSettings } from "@/components/tools/color-palette-settings";
+import { QrGenerateSettings } from "@/components/tools/qr-generate-settings";
+import { BarcodeReadSettings } from "@/components/tools/barcode-read-settings";
+// Phase 3: Layout & Composition
+import { CollageSettings } from "@/components/tools/collage-settings";
+import { SplitSettings } from "@/components/tools/split-settings";
+import { BorderSettings } from "@/components/tools/border-settings";
+// Phase 3: Format & Conversion
+import { SvgToRasterSettings } from "@/components/tools/svg-to-raster-settings";
+import { VectorizeSettings } from "@/components/tools/vectorize-settings";
+import { GifToolsSettings } from "@/components/tools/gif-tools-settings";
+// Phase 3: Optimization extras
+import { BulkRenameSettings } from "@/components/tools/bulk-rename-settings";
+import { FaviconSettings } from "@/components/tools/favicon-settings";
+import { ImageToPdfSettings } from "@/components/tools/image-to-pdf-settings";
+// Phase 3: Adjustments extra
+import { ReplaceColorSettings } from "@/components/tools/replace-color-settings";
 import * as icons from "lucide-react";
 
 const COLOR_TOOL_IDS = new Set([
@@ -21,7 +47,11 @@ const COLOR_TOOL_IDS = new Set([
   "color-effects",
 ]);
 
+// Tools that don't need a file dropzone (they generate content or have custom UI)
+const NO_DROPZONE_TOOLS = new Set(["qr-generate"]);
+
 function ToolSettingsPanel({ toolId }: { toolId: string }) {
+  // Phase 2: Core tools
   if (toolId === "resize") return <ResizeSettings />;
   if (toolId === "crop") return <CropSettings />;
   if (toolId === "rotate") return <RotateSettings />;
@@ -29,6 +59,32 @@ function ToolSettingsPanel({ toolId }: { toolId: string }) {
   if (toolId === "compress") return <CompressSettings />;
   if (toolId === "strip-metadata") return <StripMetadataSettings />;
   if (COLOR_TOOL_IDS.has(toolId)) return <ColorSettings toolId={toolId} />;
+  // Phase 3: Watermark & Overlay
+  if (toolId === "watermark-text") return <WatermarkTextSettings />;
+  if (toolId === "watermark-image") return <WatermarkImageSettings />;
+  if (toolId === "text-overlay") return <TextOverlaySettings />;
+  if (toolId === "compose") return <ComposeSettings />;
+  // Phase 3: Utilities
+  if (toolId === "info") return <InfoSettings />;
+  if (toolId === "compare") return <CompareSettings />;
+  if (toolId === "find-duplicates") return <FindDuplicatesSettings />;
+  if (toolId === "color-palette") return <ColorPaletteSettings />;
+  if (toolId === "qr-generate") return <QrGenerateSettings />;
+  if (toolId === "barcode-read") return <BarcodeReadSettings />;
+  // Phase 3: Layout & Composition
+  if (toolId === "collage") return <CollageSettings />;
+  if (toolId === "split") return <SplitSettings />;
+  if (toolId === "border") return <BorderSettings />;
+  // Phase 3: Format & Conversion
+  if (toolId === "svg-to-raster") return <SvgToRasterSettings />;
+  if (toolId === "vectorize") return <VectorizeSettings />;
+  if (toolId === "gif-tools") return <GifToolsSettings />;
+  // Phase 3: Optimization extras
+  if (toolId === "bulk-rename") return <BulkRenameSettings />;
+  if (toolId === "favicon") return <FaviconSettings />;
+  if (toolId === "image-to-pdf") return <ImageToPdfSettings />;
+  // Phase 3: Adjustments extra
+  if (toolId === "replace-color") return <ReplaceColorSettings />;
 
   return (
     <p className="text-xs text-muted-foreground italic">
@@ -69,6 +125,7 @@ export function ToolPage() {
     )[tool.icon] || icons.FileImage;
 
   const hasFile = files.length > 0;
+  const isNoDropzone = NO_DROPZONE_TOOLS.has(tool.id);
 
   return (
     <AppLayout showToolPanel={false}>
@@ -84,7 +141,8 @@ export function ToolPage() {
             </h2>
           </div>
 
-          {/* File info */}
+          {/* File info - hidden for tools that don't need files */}
+          {!isNoDropzone && (
             <div className="space-y-2">
               <h3 className="text-sm font-medium text-muted-foreground">
                 Files
@@ -115,6 +173,7 @@ export function ToolPage() {
                 </p>
               )}
             </div>
+          )}
 
           <div className="border-t border-border" />
 
@@ -129,7 +188,11 @@ export function ToolPage() {
 
         {/* Dropzone / Preview */}
         <div className="flex-1 flex items-center justify-center p-6">
-          {processedUrl && originalBlobUrl ? (
+          {isNoDropzone ? (
+            <div className="text-center text-muted-foreground">
+              <p className="text-sm">Configure settings in the panel and generate.</p>
+            </div>
+          ) : processedUrl && originalBlobUrl ? (
             <BeforeAfterSlider
               beforeSrc={originalBlobUrl}
               afterSrc={processedUrl}