flutter3d_net 0.7.0

Rollback netcode over `sim`: input frames per step, prediction, correction, and the transport behind an interface so a game never names WebRTC or a socket.

0.7.0

• The first publication. The 0.6.0 below was a number this package carried inside the workspace; it never reached pub.dev. The whole shelf goes out on one number so that one number names one tree, and ^0.7.0 on any flutter3d_* package resolves against every other. doc/boundary-0.7.0.md lists the thirteen packages that begin at this release.
• Two things the entry below leaves out, both here since the first commit. diffRuns takes two DigestTraces and a function per side that answers with the saved state at a step. DigestTrace.divergenceFromHex finds the first checkpoint that disagrees from the hex digests a .f3drun already carries, and diffRuns compares the two JSON trees at that one step and returns a SnapshotDivergence: the step, a dotted path such as entities.7.health, and the two values. It replays nothing itself, because only a genre's own package knows how to step its simulation. WebSocketTransport is the NetTransport over the relay for a platform or a NAT that a WebRTC data channel did not get through. It is built on web_socket_channel and not on dart:io, so the same class compiles for a browser, and while it is in use every game frame rides the relay.
• The relay can be deployed from the package. deploy/Dockerfile runs bin/relay.dart on port 8790 and is built from the repository root, since the package resolves flutter3d_sim inside the workspace. deploy/flutter3d-net-relay.service is a systemd unit for the same process.
• No code changed since 0.6.0 was written beyond what the formatter did. The floor on flutter3d_sim is ^0.7.0.

0.6.0

• net-01 in doc/tooling-plan.md. NetSession: input frames per step, prediction by the last frame that arrived, rollback on a disagreeing confirmation, a dropped-correction count. NetTransport as the one interface a real network implements; LoopbackTransport with a real fixed delay and seeded loss for tests that drive two sessions against each other rather than a mock that cannot lie about timing.
• net-02's relay (bin/relay.dart): rooms by a short code in the URL path, no accounts, signalling and a WebSocket fallback beside the WebRTC transport in flutter3d_net_webrtc.
• Plain Dart. Nothing here imports Flutter, and a relay process needs no SDK to run.