feat: project registry + per-project filters (stage 1 wire surface)

- listProjects() returns the shared hub's registry (general first;
  sealed areas never appear — they are their own hub instance).
- eventLog, streamEvents and listApprovals take an optional project:
  filter; LoggedEvent, PendingApprovalEntry and FlowSummary carry
  project. Stubs regenerated from the platform's hub.proto.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

CHANGELOG.md

@@ -4,6 +4,16 @@ The SDK version tracks the platform release that shipped the
 matching wire surface; see the platform repo's `CHANGELOG.md`
 for the authoritative per-release detail.
 
+## Unreleased
+
+- Projects on the wire (Studio multi-project stage ①):
+  `listProjects()` returns the shared hub's registry (`general`
+  first; sealed areas never appear — they are their own hub
+  instance); `eventLog`, `streamEvents` and `listApprovals` take
+  an optional `project:` filter; `LoggedEvent`,
+  `PendingApprovalEntry` and `FlowSummary` carry `project`.
+  Regenerated stubs from the platform's `hub.proto`.
+
 ## 0.18.x (current)
 
 - Full Hub + HubAdmin coverage: `submit` (incl. `detach:`),