docs: align wire-spec and mark implemented vs proposed

Keep the 45-byte pose frame consistent across docs, simulator, and
prototype, clarify MinIO is not peer sync, and state clearly that the
repo is a from-scratch platform sketch with options rather than mandates.

simulator/tests/test_broadcast.py

@@ -9,7 +9,7 @@ from virtual_drone.flight import Pose
 
 
 def test_frame_size_matches_wire_spec() -> None:
-    # Documented as 46 B in docs/04; struct packs to FRAME.size (45 B on this layout).
+    # Keep docs/04, the journey, and prototype/src/sim.ts POSE_BYTES in lockstep.
     assert FRAME.size == 45