- apply: `check_extension_points_provided` (app nodes) — every EP visible on
the app's chain (its own + inherited) must have a provider: a same-apply
module, or one resolvable up-chain (override or default body). Else a clean
`pic plan` error instead of a runtime failure. Single-node only (the tree
path leans on the runtime backstop, like the dangling-import check).
- read-only surface: `extension_point_report` + `ExtensionPointInfo`;
`GET /{apps|groups}/{id}/extension-points` (AppRead / GroupScriptsRead);
`pic extension-points ls --app|--group` showing declared-vs-inherited + the
resolved provider (`app override` / `inherited default` / `unset`).
- `pic pull` round-trips an app's OWN declared EPs (filtered `declared_here`),
so pull→plan stays idempotent.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
