feat(sidecar): POST /permissions/inventory forwards the plugin's store read

Protocol 13, the permission manager (PLAN_REDESIGNS section 1): one more
opaque forward. The body is {snapshotId?, page?}; paging is the plugin's
and the website's, and no page is kept here.

Refs RunicGateway/Module-Rust#21

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

sidecar/src/main.rs

@@ -171,6 +171,10 @@ use tracing_subscriber::EnvFilter;
 /// whatever its kind — so what changes here is what no longer has to fit: the reload window that
 /// had to sit inside [`rpc::REPLY_TIMEOUT`] is gone.
 ///
+/// The permission manager's redesign (the module's PLAN_REDESIGNS.md §1, D160) adds one route,
+/// `POST /permissions/inventory`: the plugin's whole store, in pages it sizes to the game link's
+/// line cap. Forwarded like every other object; the pages are never kept here.
+///
 /// `docs/rust-link/PROTOCOL.md` is the specification — §8 the read path, §9 identity, §10 the
 /// mirror, §11 configuration, §12 clans, §13 the raid frame, §14 the leases, §15 the world verbs,
 /// §16 the rewards, §17 the map, §18 the optional mods, §19 the walk's fixes; this constant is one