fix(coding-agent): use lazy-loaded photon wrapper for Node.js compatibility

Previous commit broke Node.js/tsx by using the ESM entry point which
doesn't work with Node. This creates a wrapper module that:
- Uses require() for lazy loading (works in both Node and Bun)
- Gracefully handles load failures (returns original image)
- Works in Node.js, tsx, and Bun compiled binaries

packages/coding-agent/src/utils/image-convert.ts

@@ -1,6 +1,4 @@
-// Use ESM entry point so Bun can embed the WASM in compiled binaries
-// (the CJS entry uses fs.readFileSync which breaks in standalone binaries)
-import { PhotonImage } from "@silvia-odwyer/photon-node/photon_rs_bg.js";
+import { getPhoton } from "./photon.js";
 
 /**
  * Convert image to PNG format for terminal display.
@@ -15,8 +13,14 @@ export async function convertToPng(
 		return { data: base64Data, mimeType };
 	}
 
+	const photon = getPhoton();
+	if (!photon) {
+		// Photon not available, can't convert
+		return null;
+	}
+
 	try {
-		const image = PhotonImage.new_from_byteslice(new Uint8Array(Buffer.from(base64Data, "base64")));
+		const image = photon.PhotonImage.new_from_byteslice(new Uint8Array(Buffer.from(base64Data, "base64")));
 		try {
 			const pngBuffer = image.get_bytes();
 			return {

packages/coding-agent/src/utils/image-resize.ts

@@ -1,7 +1,5 @@
 import type { ImageContent } from "@mariozechner/pi-ai";
-// Use ESM entry point so Bun can embed the WASM in compiled binaries
-// (the CJS entry uses fs.readFileSync which breaks in standalone binaries)
-import { PhotonImage, resize, SamplingFilter } from "@silvia-odwyer/photon-node/photon_rs_bg.js";
+import { getPhoton } from "./photon.js";
 
 export interface ImageResizeOptions {
 	maxWidth?: number; // Default: 2000
@@ -55,9 +53,23 @@ export async function resizeImage(img: ImageContent, options?: ImageResizeOption
 	const opts = { ...DEFAULT_OPTIONS, ...options };
 	const inputBuffer = Buffer.from(img.data, "base64");
 
-	let image: ReturnType<typeof PhotonImage.new_from_byteslice> | undefined;
+	const photon = getPhoton();
+	if (!photon) {
+		// Photon not available, return original image
+		return {
+			data: img.data,
+			mimeType: img.mimeType,
+			originalWidth: 0,
+			originalHeight: 0,
+			width: 0,
+			height: 0,
+			wasResized: false,
+		};
+	}
+
+	let image: ReturnType<typeof photon.PhotonImage.new_from_byteslice> | undefined;
 	try {
-		image = PhotonImage.new_from_byteslice(new Uint8Array(inputBuffer));
+		image = photon.PhotonImage.new_from_byteslice(new Uint8Array(inputBuffer));
 
 		const originalWidth = image.get_width();
 		const originalHeight = image.get_height();
@@ -96,7 +108,7 @@ export async function resizeImage(img: ImageContent, options?: ImageResizeOption
 			height: number,
 			jpegQuality: number,
 		): { buffer: Uint8Array; mimeType: string } {
-			const resized = resize(image!, width, height, SamplingFilter.Lanczos3);
+			const resized = photon!.resize(image!, width, height, photon!.SamplingFilter.Lanczos3);
 
 			try {
 				const pngBuffer = resized.get_bytes();

packages/coding-agent/src/utils/photon.d.ts

@@ -1,5 +0,0 @@
-// Type declarations for the ESM entry point of @silvia-odwyer/photon-node
-// The ESM entry exports the same API but uses WASM imports that bundlers can embed
-declare module "@silvia-odwyer/photon-node/photon_rs_bg.js" {
-	export * from "@silvia-odwyer/photon-node";
-}

packages/coding-agent/src/utils/photon.ts

@@ -0,0 +1,59 @@
+/**
+ * Photon image processing wrapper.
+ *
+ * This module provides a unified interface to @silvia-odwyer/photon-node that works in:
+ * 1. Node.js (development, npm run build)
+ * 2. Bun compiled binaries (standalone distribution)
+ *
+ * The challenge: photon-node's CJS entry uses fs.readFileSync(__dirname + '/photon_rs_bg.wasm')
+ * which bakes the build machine's absolute path into Bun compiled binaries.
+ *
+ * Solution: Lazy-load photon and gracefully handle failures. Image processing functions
+ * already have fallbacks that return original images when photon isn't available.
+ */
+
+// Re-export types from the main package
+export type { PhotonImage as PhotonImageType } from "@silvia-odwyer/photon-node";
+
+// Lazy-loaded photon module
+let photonModule: typeof import("@silvia-odwyer/photon-node") | null = null;
+let loadAttempted = false;
+let loadError: Error | null = null;
+
+/**
+ * Get the photon module, loading it lazily on first access.
+ * Returns null if loading fails (e.g., in broken Bun binary).
+ */
+export function getPhoton(): typeof import("@silvia-odwyer/photon-node") | null {
+	if (loadAttempted) {
+		return photonModule;
+	}
+
+	loadAttempted = true;
+
+	try {
+		// Dynamic require to defer loading until actually needed
+		// This also allows the error to be caught gracefully
+		photonModule = require("@silvia-odwyer/photon-node");
+	} catch (e) {
+		loadError = e as Error;
+		photonModule = null;
+	}
+
+	return photonModule;
+}
+
+/**
+ * Check if photon is available and working.
+ */
+export function isPhotonAvailable(): boolean {
+	return getPhoton() !== null;
+}
+
+/**
+ * Get the error that occurred during photon loading, if any.
+ */
+export function getPhotonLoadError(): Error | null {
+	getPhoton(); // Ensure load was attempted
+	return loadError;
+}

packages/coding-agent/tsconfig.build.json

@@ -5,5 +5,5 @@
 		"rootDir": "./src"
 	},
 	"include": ["src/**/*.ts"],
-	"exclude": ["node_modules", "dist"]
+	"exclude": ["node_modules", "dist", "**/*.d.ts", "src/**/*.d.ts"]
 }