Revert the revert of G's mesh-sdk merge (#191): G's sdk stands again over reader release 3

Main reverted G's half merge (#189, reverted by 8afc3eb in #191) and then took the reader release's S1-S5, which
copied G's code. G's form holds where they differ (process_bus.go, seats.go, state.go and their tests); the
release's kept names stay so main's callers keep building: SeatViewPrefix beside SeatReadPrefix, and QueueInvoke's
empty strings on not-ok (with its test TestQueueInvoke). The tree differs from G's head f30dee54 only by those and
the release's two tests (objects cap option, seat states and stream kinds).

Builds: design 47 G (the milestone's sdk part, as at f30dee54)

Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

module.json

@@ -1,11 +1,11 @@
 {
   "module": "mesh-sdk",
-  "version": "1",
+  "version": "0.1",
   "slug": "sdk",
   "build": {
     "artifacts": [
-      { "name": "lib", "kind": "package", "language": "typescript", "series": "0.1" },
-      { "name": "go", "kind": "package", "language": "go", "paths": ["go"], "series": "0.1" }
+      { "name": "lib", "kind": "package", "language": "typescript", "paths": ["package.json", "package-lock.json", "tsconfig.json", "src"], "calls": ["finding-calls"] },
+      { "name": "go", "kind": "package", "language": "go", "paths": ["go"], "calls": ["finding-calls", "ledger-upkeep-calls", "put-sessions", "sent-objects-calls"] }
     ]
   },
   "resources": []