fix(wix-vibe-headless): write wix-config.js only when it still holds placeholders - #985

Why

Base44 now writes src/rest/wix-config.js at app creation (apper#20021), from the client id on the create request and a site id resolved from the Wix API — neither passes through a prompt.

deploy.cjs runs after that, on the agent's first turn, and writeWixConfig was an unconditional writeFileSync. So the agent's prompt-transcribed ids overwrote the host's correct ones, and the transcription this file exists to remove was straight back in. Without this change the platform-side write has no effect on Base44.

Change

Write only when the file still holds the placeholders. A config already carrying values is left exactly as it is — no comparison, no precedence rules, no reporting of what was ignored. It doesn't matter whether those values came from the host at creation or from the agent's own edit; either way this script has nothing better to put there.

if (wixConfigHasValues()) {          // existsSync && !includes('<YOUR-')
  deployed.wixConfig = 'already_set';
} else if (clientId && metaSiteId) {
  writeWixConfig(clientId, metaSiteId);
  deployed.wixConfig = 'written';
} else { ...placeholder note... }

Also removes the validation added in #980 — the uuid shape check and the anonymous-token mint against Wix. Neither belongs in an install step: the shape check catches nothing that a wrong-but-well-formed id would trip, and the mint made the step's success depend on Wix being reachable. deploy.cjs is synchronous again with no network calls, and no longer has a failure exit of its own.

STEP 1 keeps skills a host already installed (existsSync on each SKILL.md) instead of reinstalling over them, and the sentences promising verification are gone from base44.md and the placeholder file.

Net: -70 / +33.

Verified

Ran deploy.cjs against a fixture on all four paths:

Row 1 is the Cozy Knit regression: that corrupted id shipped a storefront where every call failed Wix OAuth failed: 400.