gplay vitals (post-launch quality signals)

gplay vitals reads Android vitals, the post-launch quality signals you know from the Play Console: crash rate, ANR rate, slow cold start, slow rendering, excessive wakeups, low-memory kills, stuck background wakelocks, plus error reports and Play-detected anomalies. Shared conventions (auth, output, exit codes, --package pinning) are in gplay-cli-usage.

Two things make this namespace different from the rest of gplay:

• A distinct Google service. Vitals is backed by the Play Developer Reporting API (playdeveloperreporting), not the Android Publisher API. Same service-account file, but a different OAuth scope (…/auth/playdeveloperreporting). If the service account was invited only for publishing, vitals calls fail with a 403 (exit 11) until the reporting scope is granted; that is an environment fix, not a flag.
• Read-only, always. Every vitals command only reads metrics. There is no write here, so GPLAY_READONLY never blocks it, and no command needs --confirm.