fix(net): force IPv4 and disable Happy Eyeballs in Node entrypoints

[georgemunyoro]

Problem

Connections to us.posthog.com fail when Tailscale is enabled. The root cause was traced to IPv6 EHOSTUNREACH errors during Node fetch. PostHog's many-address ELB times out the connect when IPv6 is unreachable (e.g. via Tailscale), because Node's "Happy Eyeballs" family racing abandons each IPv4 attempt before it can complete. Setting ipv4first alone is not sufficient to resolve this.

Reproduction

With Tailscale enabled, attempt to log in (against us.posthog.com — not a local localhost PostHog, which is loopback and unaffected). The login fails because the main-process OAuth token call is a Node fetch to PostHog's ELB, which times out. The same failure then affects the agent, auth-proxy and MCP proxy (all outbound Node fetch from the workspace-server child), making the app effectively unusable.

The underlying network failure can be reproduced directly:

# With Tailscale enabled — fails with AggregateError [ETIMEDOUT] after ~2s:
node -e '
const u="https://us.posthog.com/_health"; const t=Date.now();
fetch(u,{method:"HEAD",signal:AbortSignal.timeout(8000)})
  .then(r=>console.log("OK",r.status,Date.now()-t+"ms"))
  .catch(e=>console.log("FAIL",e.name,Date.now()-t+"ms"));'

# The same call succeeds once family autoselection is disabled (the fix in this PR):
node --no-network-family-autoselection --dns-result-order=ipv4first -e '
const u="https://us.posthog.com/_health"; const t=Date.now();
fetch(u,{method:"HEAD",signal:AbortSignal.timeout(8000)})
  .then(r=>console.log("OK",r.status,Date.now()-t+"ms"))
  .catch(e=>console.log("FAIL",e.name,Date.now()-t+"ms"));'

Changes

• apps/code/src/main/bootstrap.ts: Disable Happy Eyeballs via net.setDefaultAutoSelectFamily(false) in the Electron main bootstrap, complementing the existing dns.setDefaultResultOrder(\"ipv4first\") call. Added an explanatory comment about why ipv4first alone is insufficient.
• packages/workspace-server/src/serve.ts: Mirror the same network configuration (dns.setDefaultResultOrder(\"ipv4first\") + net.setDefaultAutoSelectFamily(false)) in the workspace-server entrypoint, since this child process makes all outbound HTTPS calls to PostHog and the gateway.

TL;DR Force IPv4 and disable Node's Happy Eyeballs family selection in both the Electron main process and the workspace-server entrypoint, fixing connection timeouts to PostHog's ELB when IPv6 is unreachable (e.g. under Tailscale).

How did you test this?

• Reproduced the failure by logging in with Tailscale enabled against us.posthog.com (see Reproduction above) — login failed with IPv6 EHOSTUNREACH / ETIMEDOUT errors before the fix and succeeds after it.
• Confirmed the underlying node -e repro fails with default settings and succeeds with --no-network-family-autoselection --dns-result-order=ipv4first.
• Typecheck + lint pass; connectivity service unit tests pass (16/16).

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

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Created with PostHog Code

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 7d722ea.}

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(net): force IPv4 and disable Happy E..." | Re-trigger Greptile}