refactor: Simplify R2 cache population to use local wrangler dev with remote binding

Reworks the R2 cache upload approach per reviewer feedback. Instead of
deploying the worker with a token, populating, then redeploying, we now
use a local wrangler dev worker with a remote R2 binding.

Key changes:
- Replace deploy/populate/redeploy cycle with local wrangler dev approach
- Remove --cacheMethod flag and dual code paths
- Remove token auth system (local worker needs no auth)
- Remove esbuild compilation step (wrangler accepts TS natively)
- Revert deploy.ts, worker.ts, cloudflare-context.ts, build.ts, run-wrangler.ts to main
- Delete compile-cache-populate-handler.ts

The new flow derives a temp wrangler config with the R2 binding set to
remote: true, starts wrangler dev locally, sends batched cache entries
to the worker, then stops it. Single code path for all cache sizes.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: isaacrowntree

.changeset/fix-r2-cache-upload.md

@@ -2,35 +2,17 @@
 "@opennextjs/cloudflare": minor
 ---
 
-fix: Use worker binding for R2 cache uploads to avoid API rate limits
-
-For large deployments with 500+ prerendered pages, the R2 incremental cache upload now uses the worker's R2 binding directly instead of wrangler's `r2 bulk put` command. This bypasses the Cloudflare API rate limit of 1,200 requests per 5 minutes.
-
-**New `--cacheMethod` flag:**
-```bash
-# Auto-select based on cache size (default) - uses binding for 500+ entries
-opennextjs-cloudflare deploy --cacheMethod=auto
-
-# Force wrangler CLI (original behavior)
-opennextjs-cloudflare deploy --cacheMethod=wrangler
-
-# Force worker binding (bypasses API rate limits)
-opennextjs-cloudflare deploy --cacheMethod=binding
-```
-
-The new deploy flow for large R2 caches (when using `binding` method):
-1. Deploy worker with a temporary cache populate token
-2. Send cache entries directly to the worker's `/_open-next/cache/populate` endpoint
-3. Worker writes to R2 using its binding (no API rate limits)
-4. Redeploy without the token to secure the endpoint
-
-Features:
-- Automatic threshold: Uses binding approach for caches with 500+ entries (in `auto` mode)
-- Batched uploads with configurable batch size (default: 100)
-- Retry logic with exponential backoff
-- Secure: Temporary token is removed after cache population
-- Full backward compatibility: Use `--cacheMethod=wrangler` to force original behavior
-
-This fixes the "500 Internal Server Error" during R2 cache upload for applications with thousands of prerendered pages.
+fix: Use remote R2 binding for cache population to avoid API rate limits
+
+For deployments with prerendered pages, the R2 incremental cache is now populated
+using a local wrangler dev worker with a remote R2 binding instead of `wrangler r2 bulk put`.
+This bypasses the Cloudflare API rate limit of 1,200 requests per 5 minutes that caused
+failures for large applications with thousands of prerendered pages.
+
+The new approach:
+1. Derives a temporary wrangler config from the project's config with the R2 binding set to `remote: true`
+2. Starts a local worker via `wrangler dev` with a POST endpoint
+3. Sends batched cache entries to the local worker, which writes to R2 via the binding
+4. No deployment or authentication tokens required
 
 Closes #1088

packages/cloudflare/src/api/cloudflare-context.ts

@@ -34,10 +34,6 @@ declare global {
 		// Prefix used for the R2 incremental cache bucket
 		[R2_CACHE_PREFIX_ENV_NAME]?: string;
 
-		// Token for cache population during deployment (auto-generated, temporary)
-		// This token is used by the CLI to authenticate cache population requests
-		OPEN_NEXT_CACHE_POPULATE_TOKEN?: string;
-
 		// D1 db used for the tag cache
 		NEXT_TAG_CACHE_D1?: D1Database;
 

packages/cloudflare/src/cli/build/build.ts

@@ -12,7 +12,6 @@ import { OpenNextConfig } from "../../api/config.js";
 import type { ProjectOptions } from "../project-options.js";
 import { bundleServer } from "./bundle-server.js";
 import { compileCacheAssetsManifestSqlFile } from "./open-next/compile-cache-assets-manifest.js";
-import { compileCachePopulateHandler } from "./open-next/compile-cache-populate-handler.js";
 import { compileEnvFiles } from "./open-next/compile-env-files.js";
 import { compileImages } from "./open-next/compile-images.js";
 import { compileInit } from "./open-next/compile-init.js";
@@ -83,7 +82,6 @@ export async function build(
 	await compileInit(options, wranglerConfig);
 	await compileImages(options);
 	await compileSkewProtection(options, config);
-	await compileCachePopulateHandler(options);
 
 	// Compile middleware
 	await createMiddleware(options, { forceOnlyBuildOnce: true });