- 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>
An extension point (§5.5) marks a module name a node offers for descendants
to provide/override — resolved dynamically against the inheriting app rather
than lexically sealed. Lay the storage:
- migration 0051: owner-polymorphic `extension_points(id, group_id?, app_id?,
name)` marker table — exactly-one CHECK + per-owner partial-unique LOWER(name)
indexes + lookup indexes (mirrors 0050). ON DELETE CASCADE (a marker is
config, not code). No default-body column — the optional default body is a
co-located kind=module script (Phase 4b stores/resolves/caches those).
- extension_point_repo: `list_for_owner` + idempotent `insert_extension_point_tx`
/ `delete_extension_point_tx`, keyed by the shared `ScriptOwner` (mirrors the
var/secret tx-fn style).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
