Update skills for latest PlanetScale CLI changes

[cursor]

Summary

Updates the PlanetScale skills for the 2026-08-20 changelog entries that materially affect agent guidance:

• https://planetscale.com/changelog/prefer-instant
• https://planetscale.com/changelog/cli-traffic-control-budget-list
• https://planetscale.com/changelog/cli-query-pattern-reports
• https://planetscale.com/changelog/cli-postgres-default-role
• https://planetscale.com/changelog/cli-password-show-update
• https://planetscale.com/changelog/cli-org-members
• https://planetscale.com/changelog/cli-keyspace-delete
• https://planetscale.com/changelog/cli-insights-error-anomaly-details
• https://planetscale.com/changelog/cli-deploy-request-unblock-update
• https://planetscale.com/changelog/cli-database-aggressive-cutover
• https://planetscale.com/changelog/cli-branch-update
• https://planetscale.com/changelog/cli-branch-extensions

What changed

• Corrected read-only inventory guidance for new CLI support, especially Traffic Control budget listing, default Postgres role inspection, query-pattern reports, Insights anomaly/error drill-down, password metadata, aggressive cutover state, and extension availability.
• Added a central CLI command catalog distinguishing read-only assessment commands from approval-gated mutation/destructive commands.
• Updated approval gates and operating-model guidance for password metadata updates, org member changes, keyspace deletion, deploy-request unblock/update, branch update/deletion protection, aggressive cutover, and Prefer instant.
• Added domain guidance for Vitess instant deploy risks, Postgres extension discovery, Traffic Control budget inventory, anomaly automation, and autonomous execution rollback limits.

Validation

• git diff --check HEAD~1..HEAD