The runtime for shared group collections. A script reaches a shared store via
the explicit kv::shared("name") handle (distinct GroupKvHandle Rhai type, so
private-vs-shared scope is a deliberate choice). The service resolves the
owning group from cx.app_id's ancestor chain — the script never names a group,
and that walk is the isolation boundary (a foreign app's chain never contains
the owning group → CollectionNotShared).
- shared: GroupKvService trait + GroupKvError + NoopGroupKvService; threaded
into the Services bundle as a field defaulted to noop, opted into via a new
with_group_kv() (keeps the ~14 Services::new call sites unchanged).
- manager-core: GroupKvServiceImpl with the reads-open/writes-authed split —
reads use script_gate (anonymous public scripts skip), writes use the new
script_gate_require_principal (anonymous fails closed). Owner resolution
behind a GroupCollectionResolver trait (Postgres impl + injectable fake);
unit tests cover off-chain CollectionNotShared, anonymous-read-OK/
anonymous-write-Forbidden, authed-no-role-Forbidden.
- executor-core: GroupKvHandle + kv::shared constructor + get/set/has/delete/
list (Rhai dispatches by receiver type, reusing the block_on bridge).
- picloud: wire PostgresGroupKvRepo + resolver + GroupKvServiceImpl.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>