build(cloudflare): add a Cloudflare preview build target

DEPLOY_TARGET now selects the adapter; Netlify stays the default and NODE_ADAPTER
keeps working. Cloudflare compresses in transit, so the Worker build aliases
$lib/server/compression to a pass-through that leaves the streaming body alone.

CI builds and dry-run deploys this target. That is compilation and packaging
coverage only, not a production compatibility gate: native sharp still blocks the
share-preview route in the Worker runtime.

.eslintignore

@@ -11,3 +11,5 @@ node_modules
 pnpm-lock.yaml
 package-lock.json
 yarn.lock
+
+.wrangler/

.github/workflows/tests.yml

@@ -144,3 +144,20 @@ jobs:
           if-no-files-found: ignore
       - if: always()
         run: npx supabase stop
+
+  cloudflare-preview-build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    env:
+      WRANGLER_SEND_METRICS: 'false'
+    steps:
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
+        with:
+          node-version: 24
+          cache: npm
+      - run: npm ci
+      - run: npm run build:cloudflare
+      - run: npm run check:cloudflare
+      # This is compilation/package coverage, not a production compatibility gate.
+      # Native sharp still blocks the share-preview route in the Worker runtime.

.gitignore

@@ -17,3 +17,4 @@ playwright-report
 test-results
 
 /static/sprites-grid/
+.wrangler/

.prettierignore

@@ -14,5 +14,6 @@ static/sprites-small/manifest.json
 # Machine-local editor and tool settings.
 **/*.local.json
 
-# Generated grid artwork.
+# Generated grid artwork and local Worker runtime output.
 static/sprites-grid/
+.wrangler/

adapter.mjs

@@ -2,20 +2,11 @@ import process from 'node:process';
 import AdapterNode from '@sveltejs/adapter-node';
 import AdapterNetlify from '@sveltejs/adapter-netlify';
 
-export const nodeAdapter = process.env.NODE_ADAPTER === 'true';
-
-// Netlify is the deployment target; the node adapter exists so the service worker
-// build tests can check the `build/client` layout a Node server produces, and so Lighthouse CI
-// can audit a production build. Netlify's CDN compresses responses, so precompress here to match.
+export const nodeAdapter =
+	process.env.NODE_ADAPTER === 'true' || process.env.DEPLOY_TARGET === 'node';
+export const cloudflareAdapter = process.env.DEPLOY_TARGET === 'cloudflare';
 export const adapter = nodeAdapter
 	? AdapterNode({ precompress: true })
-	: AdapterNetlify({
-			// if true, will create a Netlify Edge Function rather
-			// than using standard Node-based functions
-			edge: false,
-
-			// if true, will split your app into multiple functions
-			// instead of creating a single one for the entire app.
-			// if `edge` is true, this option cannot be used
-			split: false
-		});
+	: cloudflareAdapter
+		? (await import('@sveltejs/adapter-cloudflare')).default()
+		: AdapterNetlify({ edge: false, split: false });

package.json

@@ -45,12 +45,16 @@
 		"migrate:convert-tsv": "node scripts/convert-tsv-to-sql.js",
 		"dev:local": "./scripts/dev-local.sh && npm run dev",
 		"dev:supabase": "supabase start && npm run dev",
-		"sprites:grid": "node scripts/grid-thumbnails.mjs"
+		"sprites:grid": "node scripts/grid-thumbnails.mjs",
+		"build:cloudflare": "DEPLOY_TARGET=cloudflare npm run build",
+		"preview:cloudflare": "wrangler dev",
+		"check:cloudflare": "wrangler deploy --dry-run"
 	},
 	"devDependencies": {
 		"@lhci/cli": "^0.15.1",
 		"@playwright/test": "1.55.1",
 		"@sveltejs/adapter-auto": "^3.0.0",
+		"@sveltejs/adapter-cloudflare": "7.2.9",
 		"@sveltejs/adapter-netlify": "^4.1.0",
 		"@sveltejs/adapter-node": "^2.0.0",
 		"@sveltejs/adapter-static": "^3.0.0",
@@ -78,7 +82,8 @@
 		"tailwindcss": "^3.4.3",
 		"tslib": "^2.6.2",
 		"typescript": "^5.3.3",
-		"vitest": "^1.0.4"
+		"vitest": "^1.0.4",
+		"wrangler": "4.131.2"
 	},
 	"type": "module",
 	"dependencies": {

src/lib/server/compression.cloudflare.ts

@@ -0,0 +1,4 @@
+/** Cloudflare performs transport compression; preserve the streaming Response body. */
+export function compressResponse(_request: Request, response: Response): Response {
+	return response;
+}

svelte.config.js

@@ -10,7 +10,7 @@ const config = {
 	preprocess: vitePreprocess(),
 
 	kit: {
-		// Netlify by default, or the node adapter when NODE_ADAPTER=true. See adapter.mjs.
+		// Netlify by default; DEPLOY_TARGET selects the Cloudflare preview or Node test build.
 		adapter,
 		serviceWorker: {
 			// VitePWA owns registration. Registering here as well requests SvelteKit's default

vite.config.ts

@@ -1,10 +1,21 @@
 import { sveltekit } from '@sveltejs/kit/vite';
+import { fileURLToPath } from 'node:url';
 import { defineConfig } from 'vite';
 import { SvelteKitPWA } from '@vite-pwa/sveltekit';
 // you don't need to do this if you're using generateSW strategy in your app
 import { generateSW } from './pwa.mjs';
 
 export default defineConfig({
+	resolve: {
+		alias:
+			process.env.DEPLOY_TARGET === 'cloudflare'
+				? {
+						'$lib/server/compression': fileURLToPath(
+							new URL('./src/lib/server/compression.cloudflare.ts', import.meta.url)
+						)
+					}
+				: {}
+	},
 	plugins: [
 		sveltekit(),
 		SvelteKitPWA({

wrangler.jsonc

@@ -0,0 +1,13 @@
+{
+	"$schema": "node_modules/wrangler/config-schema.json",
+	"name": "livingdextracker-preview",
+	"main": ".svelte-kit/cloudflare/_worker.js",
+	"compatibility_date": "2026-09-15",
+	"compatibility_flags": ["nodejs_compat"],
+	"assets": {
+		"directory": ".svelte-kit/cloudflare",
+		"binding": "ASSETS"
+	},
+	"observability": { "enabled": true },
+	"vars": { "POKEDEX_PERFORMANCE": "true" }
+}