Harden Noswhere translation response handling and add failure diagnostics

[Copilot]

Malformed or empty responses from the Noswhere translation API could surface as unhandled JSON parse failures during language bootstrap and destabilize the server. This change hardens that path and adds enough response context to make production failures diagnosable.

• Guard Noswhere JSON parsing

  • Parse /langs and /translate responses from raw text instead of assuming valid JSON.
  • Convert malformed/empty bodies into provider errors with the Noswhere request id attached.
  • Prevent async language-loading failures from escaping the translator constructor.

• Improve production diagnostics

  • Log response parse failures with:
    • operation (getting translation langs / translating)
    • HTTP status and ok
    • x-noswhere-request
    • a bounded response body snippet
  • Keep the higher-level error surface concise while preserving enough detail in logs for troubleshooting.

• Add focused regression coverage

  • Cover malformed /langs responses to ensure bootstrap failures are contained and logged.
  • Cover malformed /translate responses to ensure request ids and body snippets are surfaced.

async #parseResponse(resp, action) {
    const requestId = this.#getRequestId(resp)
    const body = await resp.text()
    try {
        return JSON.parse(body)
    } catch (err) {
        console.error(
            "noswhere %s response parse error: status=%s ok=%s request=%s body=%o",
            action,
            resp.status,
            resp.ok,
            requestId,
            this.#getBodySnippet(body)
        )
        throw new Error(`error ${action}: invalid JSON response from Noswhere (request: ${requestId})`)
    }
}

[danieldaquino]

@copilot I still see this other issue:

May 20 11:47:53 purple damus-api[3841967]: node:internal/process/promises:288
May 20 11:47:53 purple damus-api[3841967]:             triggerUncaughtException(err, true /* fromPromise */);
May 20 11:47:53 purple damus-api[3841967]:             ^
May 20 11:47:53 purple damus-api[3841967]: [UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "undefined".] {
May 20 11:47:53 purple damus-api[3841967]:   code: 'ERR_UNHANDLED_REJECTION'
May 20 11:47:53 purple damus-api[3841967]: }
May 20 11:47:53 purple damus-api[3841967]: Node.js v18.19.0

Please create a new PR to address that