fix(prerenderer): HEAD requests cause double requests

[DeviaVir]

HEAD /nojs/address/... took 2530ms and returned 878259 bytes

This proves HEAD requests are generating the full HTML body (878KB) and taking 2.5 seconds - the same expensive operation as GET requests.

The code confirms this: in server.js, every request (HEAD or GET) calls render(), which runs the full Cycle.js app to generate HTML. Express handles HEAD by not sending the body, but the work is still done.

The proxy uses HEAD requests to check if pages exist (200 vs 404/500), not to get content-length. The prerender determines status codes without needing the full HTML body.

[Copilot]

Pull Request Overview

This PR optimizes HEAD request handling in the prerenderer to avoid unnecessary full HTML generation. HEAD requests are currently performing the same expensive rendering operations as GET requests (taking 2.5 seconds and generating 878KB of HTML) when they only need to determine status codes.

• Passes isHead flag through the rendering pipeline to identify HEAD requests
• Returns empty HTML content for HEAD requests while preserving status code determination
• Updates client symlink from src to dist directory

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
prerender-server/src/server.js	Adds isHead flag to render call options to identify HEAD requests
prerender-server/client	Updates symlink to point to dist instead of src directory
client/src/run-server.js	Returns empty HTML for HEAD requests while preserving status code logic

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[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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