[Feature] Add Cloudflare Worker as deployment option (#170)

* docs(cloudflare): add detailed Cloudflare Workers + R2 deploy guide

* separated cloudflare deploy guide from readme.md

* Missing R2 bucket binding for incremental cache

* docs: move Cloudflare guide to docs/ and improve documentation

- Move Cloudflare_Deploy.md to docs/ folder
- Add 'Deploy without R2' option for simple/free deployments
- Add workers.dev subdomain registration instructions
- Add missing global_fetch_strictly_public flag
- Add troubleshooting for common deployment issues
- Update README.md link to new location

* fix: conditional import for cloudflare dev and regenerate lockfile

- Use dynamic import for @opennextjs/cloudflare to avoid loading workerd during builds
- Regenerate package-lock.json with cross-platform dependencies

* fix: use main lockfile with cloudflare deps added

- Use main branch's package-lock.json as base to ensure cross-platform deps
- Add @opennextjs/cloudflare and wrangler

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Co-authored-by: dayuan.jiang <jdy.toh@gmail.com>

open-next.config.ts

@@ -0,0 +1,7 @@
+// default open-next.config.ts file created by @opennextjs/cloudflare
+import { defineCloudflareConfig } from "@opennextjs/cloudflare/config"
+import r2IncrementalCache from "@opennextjs/cloudflare/overrides/incremental-cache/r2-incremental-cache"
+
+export default defineCloudflareConfig({
+    incrementalCache: r2IncrementalCache,
+})