posthog-definitions

Add support for a new PostHog resource type (feature flag, cohort, action, survey, annotation, alert, …) to posthog-definitions. Walks through the eight files that must change, the tag-based identity convention, the load/diff/execute pipeline wiring, and the non-negotiable safety invariant. Use when the user wants to extend posthog-definitions beyond dashboards and insights.

Add support for a PostHog resource that exists exactly once per project (project settings, organization billing config, plugin enablement flags, …). Singletons do not fit the tag-based identity model — they have no collection to filter, no key to disambiguate, and no orphans to track. This skill is the playbook for the *other* shape: one declarative block, field-level diff, PATCH-only execution. Use when the user wants to manage a resource where the project itself is the only "row".

Code review guide for choosing between Result types and thrown exceptions. Recoverable, expected failures should be returned as Result values; only unrecoverable bugs and broken invariants should throw. Use when reviewing code that introduces a new error class, a new `throw`, a new `try/catch`, or a function whose failure path the caller is expected to handle.