feat: Fully use protobuf, fix controller issues and cleanup (#305)

## Description
### First commit
Restructured protobuf schemas to make them easier to use across
languages, switched to using them in-place of JSON for signaling as
well, so there's no 2 different message formats flying about. Few new
message types to deal with clients and nestri-servers better (not final
format, may see changes still).

General cleanup of dead/unused code along some bug squashing and package
updates.

TODO for future commits:
- [x] Fix additional controllers not doing inputs (possibly needs
vimputti changes)
- [x] ~~Restructure relay protocols code a bit, to reduce bloatiness of
the currently single file for them, more code re-use.~~
- Gonna keep this PR somewhat manageable without poking more at relay..
- [x] ~~Try to fix issue where with multiple clients, static stream
content causes video to freeze until there's some movement.~~
- Was caused by server tuned profile being `throughput-performance`,
causing CPU latency to be too high.
- [x] Ponder the orb


### Second + third commit
Redid the controller polling handling and fixed multi-controller
handling in vimputti and nestri code sides. Remove some dead relay code
as well to clean up the protocol source file, we'll revisit the meshing
functionality later.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added software rendering option and MangoHud runtime config;
controller sessions now support reconnection and batched state updates
with persistent session IDs.

* **Bug Fixes**
* Restored previously-filtered NES-like gamepads so they connect
correctly.

* **Chores**
* Modernized dependencies and protobuf tooling, migrated to
protobuf-based messaging and streaming, and removed obsolete CUDA build
steps.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: DatCaptainHorse <DatCaptainHorse@users.noreply.github.com>

packages/relay/internal/core/state.go

@@ -129,12 +129,11 @@ func (r *Relay) onPeerConnected(peerID peer.ID) {
 
 // onPeerDisconnected marks a peer as disconnected in our status view and removes latency info
 func (r *Relay) onPeerDisconnected(peerID peer.ID) {
+	// Relay peer disconnect handling
 	slog.Info("Mesh peer disconnected, deleting from local peer map", "peer", peerID)
-	// Remove peer from local mesh peers
 	if r.Peers.Has(peerID) {
 		r.Peers.Delete(peerID)
 	}
-	// Remove any rooms associated with this peer
 	if r.Rooms.Has(peerID.String()) {
 		r.Rooms.Delete(peerID.String())
 	}
@@ -151,18 +150,18 @@ func (r *Relay) updateMeshRoomStates(peerID peer.ID, states []shared.RoomInfo) {
 		}
 
 		// If previously did not exist, but does now, request a connection if participants exist for our room
-		existed := r.Rooms.Has(state.ID.String())
+		/*existed := r.Rooms.Has(state.ID.String())
 		if !existed {
 			// Request connection to this peer if we have participants in our local room
 			if room, ok := r.LocalRooms.Get(state.ID); ok {
-				if room.Participants.Len() > 0 {
+				if len(room.Participants) > 0 {
 					slog.Debug("Got new remote room state, we locally have participants for, requesting stream", "room_name", room.Name, "peer", peerID)
 					if err := r.StreamProtocol.RequestStream(context.Background(), room, peerID); err != nil {
 						slog.Error("Failed to request stream for new remote room state", "room_name", room.Name, "peer", peerID, "err", err)
 					}
 				}
 			}
-		}
+		}*/
 
 		r.Rooms.Set(state.ID.String(), state)
 	}