fix(dev): --share no longer publishes a 502 link on IPv6-first hosts

[fbehrens]

Problem

On hosts where localhost resolves IPv6-first (all modern macOS), vp run dev --share published a tailnet URL that answered 502 Bad Gateway:

• The dev runner's share path called ensureTailscaleServe({ localPort }) without a host, so the package default pointed tailscale serve at http://127.0.0.1:<port>.
• But the Vite dev server binds localhost (apps/web/vite.config.ts), which resolves to ::1 first on these machines — so Vite listened on IPv6 loopback only.
• Result: curl https://<host>.ts.net:<port>/ → 502, while http://localhost:<port> worked. A bracketed [::1] target is not an option — tailscaled stores it unbracketed and answers unknown proxy destination.

Fix

Pass localHost: "localhost" in the dev-share mapping so tailscaled resolves the proxy target exactly like the dev server did — the mapping and the listener agree by construction, whatever loopback family the OS prefers.

The server's own --tailscale-serve and the pair flow already pass explicit localHost values and are untouched; the 127.0.0.1 default in @t3tools/tailscale stays as-is.

Testing

• Focused test in scripts/lib/dev-share.test.ts asserts the serve invocation is now serve --bg --https=5788 http://localhost:5788; all 8 tests in the file pass.
• vp run --filter @t3tools/scripts typecheck clean for touched scope (one pre-existing unrelated suggestion), lint clean.

Worked on by ox-alpha (opencode harness).

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Note

Low Risk
Dev-only Tailscale share mapping change with a focused unit test; no production auth or data-path impact.

Overview
Fixes vp run dev --share publishing a 502 URL on IPv6-first machines (modern macOS). shareDevServer now passes localHost: "localhost" to ensureTailscaleServe so Tailscale proxies the same host Vite binds, instead of the package default 127.0.0.1.

Adds a test that captures serve args and asserts the target is http://localhost:<port>.

^{Reviewed by Cursor Bugbot for commit afe291d. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Fix --share 502 link on IPv6-first hosts by targeting localhost in shareDevServer

Updates scripts/lib/dev-share.ts to pass localHost: "localhost" to ensureTailscaleServe, aligning the Tailscale serve mapping with the host Vite actually binds. Adds a test in scripts/lib/dev-share.test.ts that captures serve invocation args via a new onServeArgs callback and asserts the target is http://localhost:5788.

^{Macroscope summarized afe291d.}

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[macroscopeapp]

Approvability

Verdict: Skipped

Macroscope did not run approvability analysis for this PR. Macroscope could not determine whether this PR modifies its approvability configuration, so the PR was not approved automatically. A PR that may change the rules that govern approval is never approved automatically.